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Home Books Laposata's Laboratory Medicine: Diagnosis of Disease in the Clinical Laboratory, 3e

Clinical Laboratory Reference Values

The conventional units in this table are the ones most commonly used in the United States. Outside the United States, SI units are the predominant nomenclature for laboratory test results. The base units in the SI system related to laboratory testing that are found in this table include the mole (amount of substance), meter (length), kilogram (mass), second (time), and Celsius (temperature).

Reference ranges vary depending on the instrument and the reagents used to perform the test. Therefore, the reference ranges shown in this table are only close approximations to the adult reference ranges found in an individual clinical laboratory. For example, coagulation tests measured in seconds until a clot forms in the tube, such as the PT and the PTT, have reference ranges that are affected by both the instrument and the reagents used to perform the test. There are more than 100 possible combinations of coagulation instruments and reagents, and, therefore, there are at least 100 different reference ranges, which are mostly similar but not identical. The cutoff value for troponin for acute myocardial infarction is at the 99th percentile of a reference range which is also instrument and reagent dependent. In addition, it is important to understand that reference ranges can be significantly affected by age and sex.

The table contains information about selected drugs for which there is no reference range because they are not present in the circulation of those not taking the drug. However, drugs which are monitored have therapeutic levels, and some of these are included in the list of reference ranges. The therapeutic range for a drug is most often established by the concentration of the drug just prior to administration of the next dose. This is called the trough level. For other drugs, the therapeutic range refers to its range at peak concentration. This varies from drug to drug and is dependent upon many factors, such as absorption, distribution within the body, and metabolism of the drug. The table does not indicate whether the therapeutic level is a peak or a trough level.

Also listed in the table are selected compounds which are neither drugs nor laboratory tests, but are compounds which can be measured in the blood and, at some concentration, become toxic. For these listings, the compound is named and the word (toxic) is listed on the same line. Conversion factors are provided in the table to allow the reader to convert conventional units to SI units and vice versa. The conversion of the conventional unit to SI unit requires a multiplication with the conversion factor, and conversion of the SI unit to the conventional unit requires division by the conversion factor.

The sample fluid is sometimes highly restrictive. For example, coagulation tests must be performed using plasma samples and serum samples are unacceptable. For other compounds, both plasma samples and serum samples may be acceptable. However, there may be differences, often minor, in the results obtained using plasma versus serum. Potassium is one such compound in which reference ranges may be different for plasma and serum. There is a significant movement away from the use of serum in favor of plasma. The principal reason for this is that extra time is required for samples to clot so that serum may be generated. A sample collected into a tube with an anticoagulant results in the generation of plasma rather than serum after the tube is centrifuged. The clotting step is omitted when plasma samples are prepared, and, therefore, the turnaround time for the performance of the test is shortened. In some circumstances, whole blood is used for analysis, but the number of tests performed using whole blood is very limited. Urine and other body fluids, such as pleural fluid and cerebrospinal fluid, are also used for testing. Some of the entries in the table are associated with a fluid other than plasma, serum, or whole blood.

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Specimen Traditional Reference Interval Traditional Units Conversion Factor, Multiply →, ← Divide SI Reference Interval SI Units
Acetaminophen (therapeutic) Serum, plasma 10–30 μg/mL 6.62 70–200 μmol/L
Acetoacetic acid Serum, plasma <1 mg/dL 0.098 <0.1 mmol/L
Acetone Serum, plasma <2.0 mg/dL 0.172 <0.34 mmol/L
Acetylcholinesterase Red blood cells 5–10 U/mL 1 5–10 U/L
Activated partial thromboplastin time (APTT) Whole blood 25–40 seconds 1 25–40 seconds
Adenosine deaminasea Serum 11.5–25.0 U/L 0.017 0.20–0.43 μKat/L
Adrenocorticotropic hormone (ACTH) (see corticotropin)
Alanineb (adult) Plasma 1.87–5.88 mg/dL 112.2 210–661 μmol/day
Alanine aminotransferase (ALT, SGPT)b Serum 10–40 U/L 1 10–40 U/L
Albuminb Serum 3.5–5.0 g/dL 10 35–50 g/L
Alcohol (see ethanol, isopropanol, methanol)
Alcohol dehydrogenasea Serum <2.8 U/L 0.017 <0.05 μKat/L
Aldolasea,b Serum 1.0–7.5 U/L 0.017 0.02–0.13 μKat/L
Aldosteroneb (upright) Plasma 7–30 ng/dL 0.0277 0.19–0.83 nmol/L
Aldosterone Urine, 24 h 3–20 μg/24 h 2.77 8–55 nmol/day
Alkaline phosphataseb Serum 50–120 U/L 1 50–120 U/L
α1-Acid glycoprotein Serum 50–120 mg/dL 0.01 0.5–1.2 g/L
α2-Macroglobulin Serum 130–300 mg/dL 0.01 1.3–3.0 g/L
Alprazolam (therapeutic) Serum, plasma 10–50 ng/mL 3.24 32–162 nmol/L
Aluminum Serum, plasma <6 ng/mL 37.06 0.0–222.4 nmol/L
Amikacin (therapeutic) Serum, plasma 20–30 μg/mL 1.71 34–52 μmol/L
Amino acid fractionation:
Alanineb Plasma 1.87–5.89 mg/dL 112.2 210–661 μmol/L
α-Aminobutyric acidb Plasma 0.08–0.36 mg/dL 97 8–35 μmol/L
Arginineb Plasma 0.37–2.40 mg/dL 57.4 21–138 μmol/L
Asparagineb Plasma 0.40–0.91 mg/dL 75.7 30–69 μmol/L
Aspartic acidb Plasma <0.3 mg/dL 75.1 <25 μmol/L
Citrullineb Plasma 0.2–1.0 mg/dL 57.1 12–55 μmol/L
Cystineb Plasma 0.40–1.40 mg/dL 83.3 33–117 μmol/L
Glutamic acidb Plasma 0.2–2.8 mg/dL 67.97 15–190 μmol/L
Glutamineb Plasma 6.1–10.2 mg/dL 68.42 420–700 μmol/L
Glycineb Plasma 0.9–4.2 mg/dL 133.3 120–560 μmol/L
Histidineb Plasma 0.5–1.7 mg/dL 64.5 32–110 μmol/L
Hydroxyprolineb Plasma <0.55 mg/dL 76.3 <42 μmol/L
Isoleucineb Plasma 0.5–1.3 mg/dL 76.24 40–100 μmol/L
Leucineb Plasma 1.0–2.3 mg/dL 76.3 75–175 μmol/L
Lysineb Plasma 1.2–3.5 mg/dL 68.5 80–240 μmol/L
Methionineb Plasma 0.1–0.6 mg/dL 67.1 6–40 μmol/L
Ornithineb Plasma 0.4–1.4 mg/dL 75.8 30–106 μmol/L
Phenylalanineb Plasma 0.6–1.5 mg/dL 60.5 35–90 μmol/L
Prolineb Plasma 1.2–3.9 mg/dL 86.9 104–340 μmol/L
Serineb Plasma 0.7–2.0 mg/dL 95.2 65–193 μmol/L
Taurineb Plasma 0.3–2.1 mg/dL 80 24–168 μmol/L
Threonineb Plasma 0.9–2.5 mg/dL 84 75–210 μmol/L
Tryptophanb Plasma 0.5–1.5 mg/dL 48.97 25–73 μmol/L
Tyrosineb Plasma 0.4–1.6 mg/dL 55.19 20–90 μmol/L
Valineb Plasma 1.7–3.7 mg/dL 85.5 145–315 μmol/L
α-Aminobutyric acidb Plasma 0.08–0.36 mg/dL 97 8–35 μmol/L
Amiodarone (therapeutic) Serum, plasma 0.5–2.5 μg/mL 1.55 0.8–3.9 μmol/L
δ-Aminolevulinic acid Urine 1.0–7.0 mg/24 h 7.626 8–53 μmol/day
Amitriptyline (therapeutic) Serum, plasma 80–250 ng/mL 3.61 289–903 nmol/L
Ammonia (as NH3)b Plasma 15–50 μg/dL 0.714 11–35 μmol/L
Amobarbital (therapeutic) Serum 1–5 μg/mL 4.42 4–22 μmol/L
Amoxapine (therapeutic) Plasma 200–600 ng/mL 1 200–600 μg/L
Amylasea,b Serum 27–130 U/L 0.017 0.46–2.21 μKat/L
Androstenedione,b male Serum 75–205 ng/dL 0.0349 2.6–7.2 nmol/L
Androstenedione,b female Serum 85–275 ng/dL 0.0349 3.0–9.6 nmol/L
Angiotensin I Plasma <25 pg/mL 1 <25 ng/L
Angiotensin II Plasma 10–60 pg/mL 1 10–60 ng/L
Angiotensin-converting enzyme (ACE)a,b Serum 8–52 U/L 0.017 0.14–0.88 μKat/L
Anion gap (Na+)−(Cl− + HCO3−) Serum, plasma 8–16 mEq/L 1 8–16 nmol/L
Antidiuretic hormone (ADH, vasopressin) (varies with osmolality) Plasma 1–5 pg/mL 0.926 0.9–4.6 pmol/L
Antiplasmin Plasma 80–130 % 0.01 0.8–1.3 Fraction of 1.0
Antithrombin activity Plasma 80–130 % 0.01 0.8–1.3 Fraction of 1.0
α1-Antitrypsin Serum 80–200 mg/dL 0.01 0.8–2.0 g/L
Apolipoprotein Ab:
Male Serum 80–151 mg/dL 0.01 0.8–1.5 g/L
Female Serum 80–170 mg/dL 0.01 0.8–1.7 g/L
Apolipoprotein Bb:
Male Serum, plasma 50–123 mg/dL 0.01 0.5–1.2 g/L
Female Serum, plasma 25–120 mg/dL 0.01 0.25–1.20 g/L
Arginineb Plasma 0.37–2.40 mg/dL 57.4 21–138 μmol/L
Arsenic (As) Whole blood <23 μg/L 0.0133 <0.31 μmol/L
Arsenic (As) (chronic poisoning) Whole blood 100–500 μg/L 0.0133 1.33–6.65 μmol/L
Arsenic (As) (acute poisoning) Whole blood 600–9300 μg/L 0.0133 7.9–123.7 μmol/L
Ascorbate, ascorbic acid (see vitamin C)
Asparagineb Plasma 0.40–0.91 mg/dL 75.7 30–69 μmol/L
Aspartate aminotransferase (AST, SGOT)a,b Serum 20–48 U/L 0.017 0.34–0.82 μKat/L
Aspartic acidb Plasma <0.3 mg/dL 75.1 <25 μmol/L
Atrial natriuretic hormone Plasma 20–77 pg/mL 1 20–77 ng/L
Barbiturates (see individual drugs; pentobarbital, phenobarbital, thiopental)
Basophils (see complete blood count, white blood cell count)
Benzodiazepines (see individual drugs; alprazolam, chlordiazepoxide, diazepam, lorazepam)
Beryllium (toxic) Urine >20 μg/L 0.111 >2.22 μmol/L
Bicarbonate Plasma 21–28 mEq/L 1 21–28 mmol/L
Bile acids (total) Serum 0.3–2.3 μg/mL 2.448 0.73–5.63 μmol/L
Bilirubin:
Totalb Serum 0.3–1.2 mg/dL 17.1 2–18 μmol/L
Direct (conjugated) Serum <0.2 mg/dL 17.1 <3.4 μmol/L
Biotin Whole blood, serum 200–500 pg/mL 0.0041 0.82–2.05 nmol/L
Bismuth (therapeutic) Whole blood 1–12 μg/L 4.785 4.8–57.4 nmol/L
Blood gases:
Pco2 Arterial blood 35–45 mm Hg 1 35–45 mm Hg
pH Arterial blood 7.35–7.45 — 1 7.35–7.45 —
Po2 Arterial blood 80–100 mm Hg 1 80–100 mm Hg
Blood urea nitrogen (BUN, see urea nitrogen)
Brain natriuretic peptide (BNP) Plasma <100 pg/mL 1 <100 pg/mL
Bupropion (therapeutic) Serum, plasma 25–100 ng/mL 3.62 91–362 nmol/L
C1 esterase inhibitor Serum 12–30 mg/dL 0.01 0.12–0.30 g/L
C3 complementb Serum 1200–1500 μg/mL 0.001 1.2–1.5 g/L
C4 complementb Serum 350–600 μg/mL 0.001 0.35–0.60 g/L
CA125 Serum <35 U/mL 1 <35 kU/L
CA19-9 Serum <37 U/mL 1 <37 kU/L
CA15-3 Serum <30 U/mL 1 <30 kU/L
CA27.29 Serum <37.7 U/mL 1 <37.7 kU/L
Cadmium (nonsmoker) Whole blood 0.3–1.2 μg/L 8.897 2.7–10.7 nmol/L
Caffeine (therapeutic, infants) Serum, plasma 8–20 μg/mL 5.15 41–103 μmol/L
Calciferol (see vitamin D)
Calcitonin Serum, plasma <19 pg/mL 1 <19 ng/L
Calcium, ionized Serum 4.60–5.08 mg/dL 0.25 1.15–1.27 mmol/L
Calcium, total Serum 8.2–10.2 mg/dL 0.25 2.05–2.55 mmol/L
Calcium, normal diet Urine <250 mg/24 h 0.025 <6.2 mmol/day
Carbamazepine (therapeutic) Serum, plasma 8–12 μg/mL 4.23 34–51 μmol/L
Carbon dioxide Serum, plasma, venous blood 22–28 mEq/L 1 22–28 mmol/L
Carboxyhemoglobin (carbon monoxide), as fraction of hemoglobin saturation:
Nonsmoker Whole blood <2.0 % 0.01 <0.02 Fraction of 1.0
Toxic Whole blood >20 % 0.01 >0.2 Fraction of 1.0
β-Carotene Serum 10–85 μg/dL 0.0186 0.2–1.6 μmol/L
Catecholamines, total (see norepinephrine)
CEA, nonsmoker Serum <3 ng/mL 1 <3 μg/L
CEA, smoker Serum <5 ng/mL 1 <5 μg/L
Ceruloplasminb Serum 20–40 mg/dL 10 200–400 mg/L
Chloramphenicol (therapeutic) Serum 10–25 μg/mL 3.1 31–77 μmol/L
Chlordiazepoxide (therapeutic) Serum, plasma 0.7–1.0 μg/mL 3.34 2.3–3.3 μmol/L
Chloride Serum, plasma 96–106 mEq/L 1 96–106 mmol/L
Chloride CSF 118–132 mEq/L 1 118–132 mmol/L
Chlorpromazine (therapeutic, adult) Plasma 50–300 ng/mL 3.14 157–942 nmol/L
Chlorpromazine (therapeutic, child) Plasma 40–80 ng/mL 3.14 126–251 nmol/L
Chlorpropamide (therapeutic) Plasma 75–250 mg/L 3.61 270–900 μmol/L
Cholesterol, high-density lipoproteins (HDL):
Optimal Plasma >60 mg/dL 0.02586 >1.55
Adequate Plasma 40–60 mg/dL 0.02586 1.03–1.55 mmol/L
High risk for heart disease Plasma <40 mg/dL 0.02586 <1.03 mmol/L
Cholesterol, low-density lipoproteins (LDL)b:
Optimal Plasma <100 mg/dL 0.02586 <2.59 mmol/L
Near optimal Plasma 100–129 mg/dL 0.02586 2.59–3.34 mmol/L
Borderline high Plasma 130–159 mg/dL 0.02586 3.37–4.12 mmol/L
High Plasma 160–189 mg/dL 0.02586 4.15–4.90 mmol/L
Very high Plasma >190 mg/dL 0.02586 >4.90 mmol/L
Cholesterol total, adult:
Desirable Serum <200 mg/dL 0.02586 <5.17 mmol/L
Borderline high Serum 200–239 mg/dL 0.02586 5.17–6.18 mmol/L
High Serum >240 mg/dL 0.02586 >6.21 mmol/L
Cholesterol total, children:
Desirable Serum <170 mg/dL 0.02586 4.4 mmol/L
Borderline high Serum 170–199 mg/dL 0.02586 4.40–5.15 mmol/L
High Serum >200 mg/dL 0.02586 >5.18 mmol/L
Chromium Whole blood 0.7–28.0 μg/L 19.2 13.4–538.6 nmol/L
Citrate Serum 1.2–3.0 mg/dL 52.05 60–160 μmol/L
Citrullineb Plasma 0.4–2.4 mg/dL 57.1 20–135 μmol/L
Clonazepam (therapeutic) Serum 15–60 ng/mL 3.17 48–190 nmol/L
Coagulation factor I (fibrinogen) Plasma 150–400 mg/dL 0.01 1.5–4.0 g/L
Coagulation factor II (prothrombin) Plasma 60–140 % 0.01 0.60–1.40 Fraction of 1.0
Coagulation factor V Plasma 60–140 % 0.01 0.60–1.40 Fraction of 1.0
Coagulation factor VII Plasma 60–140 % 0.01 0.60–1.40 Fraction of 1.0
Coagulation factor VIII Plasma 50–200 % 0.01 0.50–2.00 Fraction of 1.0
Coagulation factor IX Plasma 60–140 % 0.01 0.60–1.40 Fraction of 1.0
Coagulation factor X Plasma 60–140 % 0.01 0.60–1.40 Fraction of 1.0
Coagulation factor XI Plasma 60–140 % 0.01 0.60–1.40 Fraction of 1.0
Coagulation factor XII Plasma 60–140 % 0.01 0.60–1.40 Fraction of 1.0
Cobalt Serum <1.0 μg/L 16.97 <17 nmol/L
Codeine (therapeutic) Serum 10–100 ng/mL 3.34 33–334 nmol/L
Complete blood count (CBC):
Hematocritb:
Male Whole blood 41–50 % 0.01 0.41–0.50 Fraction of 1.0
Female Whole blood 35–45 % 0.01 0.35–0.45 Fraction of 1.0
Hemoglobin (mass concentration)b:
Male Whole blood 13.5–17.5 g/dL 10 135–175 g/L
Female Whole blood 12.0–15.5 g/dL 10 120–155 g/L
Hemoglobin (substance concentration, Hb [Fe]):
Male Whole blood 13.6–17.2 g/dL 0.6206 8.44–10.65 mmol/L
Female Whole blood 12.0–15.0 g/dL 0.6206 7.45–9.30 mmol/L
Mean corpuscular hemoglobin (MCH), mass concentrationb Whole blood 27–33 pg/cell 1 27–33 pg/cell
MCH, substance concentration, Hb [Fe] Whole blood 27–33 pg/cell 0.06206 1.70–2.05 fmol
Mean corpuscular hemoglobin concentration (MCHC), mass concentration Whole blood 33–37 g Hb/dL 10 330–370 g Hb/L
MCHC, substance concentration, Hb [Fe] Whole blood 33–37 g Hb/dL 0.6206 20–23 mmol/L
Mean cell volume (MCV)b Whole blood 80–100 μm3 1 80–100 fL
Platelet count Whole blood 150–450 103 μL−1 1 150–450 109 L−1
Red blood cell count:
Female Whole blood 3.9–5.5 106 μL−1 1 3.9–5.5 1012 L−1
Male Whole blood 4.6–6.0 106 μL−1 1 4.6–6.0 1012 L−1
Reticulocyte countb Whole blood 25–75 103 μL−1 1 25–75 109 L−1
Reticulocyte countb (fraction) Whole blood 0.5–1.5 % of RBCs 0.01 0.005–0.015 Fraction of RBCs
White blood cell countb Whole blood 4.5–11.0 103 μL−1 1 4.5–11.0 109 L−1
Differential countb (absolute):
Neutrophils Whole blood 1800–7800 μL−1 1 1.8–7.8 109 L−1
Bands Whole blood 0–700 μL−1 1 0.00–0.70 109 L−1
Lymphocytes Whole blood 1000–4800 μL−1 1 1.0–4.8 109 L−1
Monocytes Whole blood 0–800 μL−1 1 0.00–0.80 109 L−1
Eosinophils Whole blood 0–450 μL−1 1 0.00–0.45 109 L−1
Basophils Whole blood 0–200 μL−1 1 0.00–0.20 109 L−1
Differential countb (number fraction):
Neutrophils Whole blood 56 % 0.01 0.56 Fraction of 1.0
Bands Whole blood 3 % 0.01 0.03 Fraction of 1.0
Lymphocytes Whole blood 34 % 0.01 0.34 Fraction of 1.0
Monocytes Whole blood 4 % 0.01 0.04 Fraction of 1.0
Eosinophils Whole blood 2.7 % 0.01 0.027 Fraction of 1.0
Basophils Whole blood 0.3 % 0.01 0.003 Fraction of 1.0
Copperb Serum 70–140 μg/dL 0.1574 11.0–22.0 μmol/L
Coproporphyrin Urine <200 μg/24 h 1.527 <300 nmol/day
Corticotropinb (08:00) Plasma <120 pg/mL 0.22 <26 pmol/L
Cortisol, totalb:
Time of day:
8:00 Plasma 5–25 μg/dL 27.6 138–690 nmol/L
16:00 Plasma 3–16 μg/dL 27.6 83–442 nmol/L
20:00 Plasma <50% of 08:00 μg/dL 1 <50% of 08:00 nmol/L
Cortisol, freeb Urine 30–100 μg/24 h 2.76 80–280 nmol/day
Cotinine (smoker) Plasma 16–145 ng/mL 5.68 91–823 nmol/L
C-peptide Serum 0.5–3.5 ng/mL 0.333 0.17–1.17 nmol/L
Creatine, male Serum 0.2–0.7 mg/dL 76.3 15.3–53.3 μmol/L
Creatine, female Serum 0.3–0.9 mg/dL 76.3 22.9–68.6 μmol/L
Creatine kinase (CK)a Serum 50–200 U/L 0.017 0.85–3.40 μKat/L
CK-MB fraction Serum <6 % 0.01 <0.06 Fraction of 1.0
Creatinineb Serum, plasma 0.6–1.2 mg/dL 88.4 53–106 μmol/L
Creatinine Urine 1–2 g/24 h 8.84 8.8–17.7 mmol/day
Creatinine clearance, glomerular filtration rate Serum, urine 75–125 mL/min/1.73 m2 0.00963 0.72–1.2 mL/s/m2
C-telopeptide:
Men Serum, plasma 60–700 pg/mL 1 60–700 pg/mL
Premenopausal women Serum, plasma 40–465 pg/mL 1 40–465 pg/mL
Cyanide (toxic) Whole blood >1.0 μg/mL 38.4 >38.4 μmol/L
Cyanocobalamin (see vitamin B12)
Cyclic adenosine monophosphate (cAMP) Plasma 4.6–8.6 ng/mL 3.04 14–26 nmol/L
Cyclosporine (toxic) Whole blood >400 ng/mL 0.832 >333 nmol/L
Cystineb Plasma 0.40–1.40 mg/dL 83.3 33–117 μmol/L
D-dimerb Plasma Negative (<500) ng/mL 1 Negative (<500) ng/mL
Dehydroepiandrosterone (DHEA) (unconjugated, male)b Plasma, serum 180–1250 ng/dL 0.0347 6.2–43.3 nmol/L
Dehydroepiandrosterone sulfate (DHEA-S) (male)b Plasma, serum 10–619 μg/dL 0.027 0.3–16.7 μmol/L
Desipramine (therapeutic) Plasma, serum 50–200 ng/mL 3.75 170–700 nmol/L
Diazepam (therapeutic) Plasma, serum 100–1000 ng/mL 0.00351 0.35–3.51 μmol/L
Digoxin (therapeutic) Plasma 0.5–2.0 ng/mL 1.281 0.6–2.6 nmol/L
Disopyramide (therapeutic) Plasma, serum 2.8–7.0 mg/L 2.95 8–21 μmol/L
Doxepin (therapeutic) Plasma, serum 150–250 ng/mL 3.58 540–890 nmol/L
Electrolytes:
Chloride Serum, plasma 96–106 mEq/L 1 96–106 mmol/L
Carbon dioxide (CO2) Serum, plasma, venous blood 22–28 mEq/L 1 22–28 mmol/L
Potassium Plasma 3.5–5.0 mEq/L 1 3.5–5.0 mmol/L
Sodiumb Plasma 136–142 mEq/L 1 136–142 mmol/L
Eosinophils (see complete blood count, white blood cell count)
Epinephrine (supine) Plasma <50 pg/mL 5.46 <273 pmol/L
Epinephrineb Urine <20 μg/24 h 5.46 <109 nmol/day
Erythrocyte count (see complete blood count, red blood cell count)
Erythrocyte sedimentation rate (ESR)b Whole blood 0–20 mm/h 1 0–20 mm/h
Erythropoietin Serum 5–36 mU/mL 1 5–36 IU/L
Estradiol (E2, unconjugated),b female:
Follicular phase Serum 20–350 pg/mL 3.69 73–1285 pmol/L
Midcycle peak Serum 150–750 pg/mL 3.69 551–2753 pmol/L
Luteal phase Serum 30–450 pg/mL 3.69 110–1652 pmol/L
Postmenopausal Serum <59 pg/mL 3.69 <218 pmol/L
Estradiol (unconjugated),b male Serum <20 pg/mL 3.67 <184 pmol/L
Estriol (E3, unconjugated), males and nonpregnant females, varies with length of gestation Serum <2 ng/mL 3.47 <6.9 nmol/L
Estrogens (total),b female:
Follicular phase Serum 60–200 pg/mL 1 60–200 ng/L
Luteal phase Serum 160–400 pg/mL 1 160–400 ng/L
Postmenopausal Serum <130 pg/mL 1 <130 ng/L
Estrogens (total),b male Serum 20–80 pg/mL 1 20–80 ng/L
Estrone (E1),b female:
Follicular phase Plasma, serum 100–250 pg/mL 3.69 370–925 pmol/L
Luteal phase Plasma, serum 15–200 pg/mL 3.69 55–740 pmol/L
Postmenopausal Plasma, serum 15–55 pg/mL 3.69 55–204 pmol/L
Estrone (E1),b male Plasma, serum 15–65 pg/mL 3.69 55–240 pmol/L
Ethanol (ethyl alcohol) (legal intoxication—2 levels listed) Serum, whole blood >80 / >100 mg/dL 0.2171 >17.4 / 21.7 mmol/L
Ethosuximide (therapeutic) Plasma, serum 40–100 μg/mL 7.08 283–708 μmol/L
Ethylene glycol (toxic) Plasma, serum >30 mg/dL 0.1611 >5 mmol/L
Everolimus (therapeutic) Whole blood 3–15 ng/mL 1.04 5–16 nmol/L
Fatty acids (nonesterified) Plasma 8–25 mg/dL 0.0354 0.28–0.89 mmol/L
Fecal fat (as stearic acid) Stool 2.0–6.0 g/day 1 2–6 g/day
Felbamate (therapeutic) Serum, plasma 30–60 μg/mL 4.2 126–252 μmol/L
Ferritinb Plasma 15–200 ng/mL 1 15–200 μg/L
α-Fetoproteinb Serum <10 ng/mL 1 <10 μg/L
Fibrinogen Plasma 150–400 mg/dL 0.01 1.5–4.0 g/L
Fibrin breakdown products (fibrin split products) Serum <10 μg/mL 1 <10 mg/L
Folate (folic acid) Red blood cells 166–640 ng/mL 2.266 376–1450 nmol/L
Folate (folic acid) Serum 5–25 ng/mL 2.266 11–57 nmol/L
Follicle-stimulating hormone (FSH),b female:
Follicular phase Serum 1.37–9.9 mIU/mL 1 1.3–9.9 IU/L
Ovulatory phase Serum 6.17–17.2 mIU/mL 1 6.1–17.2 IU/L
Luteal phase Serum 1.09–9.2 mIU/mL 1 1.0–9.2 IU/L
Postmenopausal Serum 19.3–100.6 mIU/mL 1 19.3–100.6 IU/L
FSHb male Serum 1.42–15.4 mIU/mL 1 1.4–15.4 IU/L
FSHb female Urine 2–15 IU/24 h 1 2–15 IU/day
FSHb male Urine 3–12 IU/24 h 1 3–11 IU/day
Fructosamineb Serum 1.5–2.7 mmol/L 1 1.5–2.7 mmol/L
Gabapentin (therapeutic) Serum, plasma 2–20 μg/mL 5.84 12–117 μmol/L
Gastrin (fasting) Serum <100 pg/mL 1 <100 ng/L
Gentamicin (therapeutic) Serum 6–10 μg/mL 2.1 12–21 μmol/L
Glucagonb Plasma 20–100 pg/mL 1 20–100 ng/L
Glucoseb Serum, plasma 70–110 mg/dL 0.05551 3.9–6.1 mmol/L
Glucose CSF 50–80 mg/dL 0.05551 2.8–4.4 mmol/L
Glucose-6-phosphate dehydrogenase Red blood cells 10–14 U/g of Hb 0.0645 0.65–0.90 U/mol of Hb
Glutamic acidb Plasma 0.2–2.8 mg/dL 67.97 15–190 μmol/L
Glutamine Plasma 6.1–10.2 mg/dL 68.42 420–700 μmol/L
γ-Glutamyltransferase (GGT; γ-glutamyl transpeptidase)b:
Female Serum <30 U/L 0.017 0.51 μKat/L
Male Serum <50 U/L 0.017 <0.85 μKat/L
Glycerol (free)b Serum <1.5 mg/dL 0.1086 <0.16 mmol/L
Glycineb Plasma 0.9–4.2 mg/dL 133.3 120–560 μmol/L
Glycated hemoglobin (hemoglobin A1, A1c):
Whole blood Whole blood 4–5.6 % of total Hb 1 4–5.6 Fraction of total Hb
Gold (therapeutic) Serum 100–200 μg/dL 0.05077 5.1–10.2 μmol/L
Growth hormone, adult (GH, somatotropin)b Plasma, serum <10 ng/mL 1 <10 μg/L
Haloperidol (therapeutic) Serum, plasma 5–20 ng/mL 2.6 13–52 nmol/L
Haptoglobinb Serum 40–180 mg/dL 0.01 0.4–1.8 g/L
Hematocrit (see complete blood count)
Hemoglobin (see complete blood count)
Hemoglobin A1c (see glycated hemoglobin)
Hemoglobin A2b Whole blood 2.0–3.5 % total Hb 2.0–3.5 Fraction of 1.0
Hemoglobin Fb (fetal hemoglobin in adult) Whole blood <2 % 0.01 <2 Fraction of 1.0
Histidineb Plasma 0.5–1.7 mg/dL 64.5 32–110 μmol/L
Homocysteine (total) Plasma, serum 4–12 μmol/L 1 4–12 μmol/L
Homovanillic acidb Urine <8 mg/24 h 5.489 <45 μmol/day
Human chorionic gonadotropin (hCG) (nonpregnant adult female) Serum <3 mIU/mL 1 <3 IU/L
β-Hydroxybutyric acid Serum 0.21–2.81 mg/dL 96.05 20–270 μmol/L
5-Hydroxyindoleacetic acid (5-HIAA) Urine <25 mg/24 h 5.23 <131 μmol/day
17α-Hydroxyprogesterone,b female:
Follicular phase Serum 15–70 ng/dL 0.03 0.4–2.1 nmol/L
Luteal phase Serum 35–290 ng/dL 0.03 1.0–8.7 nmol/L
Postmenopausal Serum <70 ng/dL 0.03 <2.1 nmol/L
17α-Hydroxyprogesterone,b male Serum 27–199 ng/dL 0.03 0.8–6.0 nmol/L
Hydroxyproline Plasma <0.55 mg/dL 76.3 <42 μmol/L
5-Hydroxytryptamine (see serotonin)
Ibuprofen (therapeutic) Serum, plasma 10–50 μg/mL 4.85 49–243 μmol/L
Imipramine (therapeutic) Serum, plasma 150–250 ng/mL 3.57 536–893 nmol/L
Immunoglobulin A (IgA)b Serum 50–350 mg/dL 0.01 0.5–3.5 g/L
Immunoglobulin D (IgD) Serum 0.5–3.0 mg/dL 10 5–30 mg/L
Immunoglobulin E (IgE) Serum 10–179 IU/mL 2.4 24–430 μg/L
Immunoglobulin G (IgG)b Serum 600–1560 mg/dL 0.01 6.0–15.6 g/L
Immunoglobulin M (IgM)b Serum 54–222 mg/dL 0.01 0.5–2.2 g/L
Insulin Plasma 5–20 μU/mL 6.945 34.7–138.9 pmol/L
Inhibin A:
Males Serum 1.0–3.6 pg/mL 1 1.0–3.6 ng/L
Female, early follicular Serum 5.5–28.2 pg/mL 1 5.5–28.2 ng/L
Female, late follicular Serum 19.5–102.3 pg/mL 1 19.5–102.3 ng/L
Female, midcycle Serum 49.9–155.5 pg/mL 1 49.9–155.5 ng/L
Female, midluteal Serum 13.2–159.6 pg/mL 1 13.2–159.6 ng/L
Female, postmenopausal Serum 1.0–3.9 pg/mL 1 1.0–3.9 ng/L
Insulin C-peptide (see C-peptide)
Insulin-like growth factorb Serum 130–450 ng/mL 1 130–450 μg/L
Ionized calcium (see calcium)
Iron (total)b Serum 60–150 μg/dL 0.179 10.7–26.9 μmol/L
Iron-binding capacity Serum 250–400 μg/dL 0.179 44.8–71.6 μmol/L
Isoleucineb Plasma 0.5–1.3 mg/dL 76.24 40–100 μmol/L
Isoniazid (therapeutic) Plasma or serum 1–7 μg/mL 7.29 7–51 μmol/L
Isopropanol (toxic) Plasma, serum >400 mg/L 0.0166 >6.64 mmol/L
Lactate (lactic acid) Arterial blood 3–11.3 mg/dL 0.111 0.3–1.3 mmol/L
Lactate (lactic acid) Venous blood 4.5–19.8 mg/dL 0.111 0.5–2.2 mmol/L
Lactate dehydrogenase (LDH, LD) Serum 50–200 U/L 1 50–200 U/L
Lamotrigine (therapeutic) Serum, plasma 2.5–15 μg/dL 3.91 10–59 μmol/L
Lead (toxic) Whole blood >5 μg/dL 0.0483 >0.24 μmol/L
Leucineb Plasma 1.0–2.3 mg/dL 76.3 75–175 μmol/L
Leukocyte count (see complete blood count, white blood cell count)
Levetiracetam (therapeutic) Serum, plasma 12–46 μg/mL 5.88 71–270 μmol/L
Lidocaine (therapeutic) Serum, plasma 1.5–6.0 μmL g/mL 4.27 6.4–25.6 μmol/L
Lipasea Serum 0–160 U/L 0.017 0–2.72 μKat/L
Lipoprotein(a) (Lp(a)) Serum, plasma 10–30 mg/dL 0.01 0.1–0.3 g/L
Lithium (therapeutic) Serum, plasma 0.6–1.2 mEq/L 1 0.6–1.2 mmol/L
Lorazepam (therapeutic) Serum, plasma 50–240 ng/mL 3.11 156–746 nmol/L
Luteinizing hormone (LH),b female:
Follicular phase Serum 2.0–15.0 mIU/L 1 2.0–15.0 IU/L
Ovulatory peak Serum 22.0–105.0 mIU/L 1 22.0–105.0 IU/L
Luteal phase Serum 0.6–19.0 mIU/L 1 0.6–19.0 IU/L
Postmenopausal Serum 16.0–64.0 mIU/L 1 16.0–64.0 IU/L
Luteinizing hormone (LH),b male Serum 2.0–12.0 mIU/L 1 2.0–12.0 IU/L
Lymphocytes (see complete blood count, white blood cell count)
Lysineb Plasma 1.2–3.5 mg/dL 68.5 80–240 μmol/L
Lysozyme (muramidase) Serum 4–13 mg/L 1 4–13 mg/L
Magnesiumb Serum 1.5–2.5 mg/dL 0.4114 0.62–1.03 mmol/L
Manganese Whole blood 10–12 μg/L 18.2 182–218 nmol/L
Maprotiline (therapeutic) Plasma, serum 200–600 ng/mL 1 200–600 μg/L
MCH (see complete blood count)
MCHC (see complete blood count)
Meperidine (therapeutic) Serum, plasma 0.4–0.7 μg/mL 4.04 1.6–2.8 μmol/L
Mercury Whole blood 0.6–59.0 μg/L 4.99 3.0–294.4 nmol/L
Metanephrines (total)b Urine <1.0 mg/24 h 5.07 <5 μmol/day
Methadone (therapeutic) Serum, plasma 100–400 ng/mL 0.00323 0.32–1.29 μmol/L
Methanol (toxic) Whole blood, serum >1.5 mg/L 0.0312 >0.05 mmol/L
Methemoglobin Whole blood <0.24 g/dL 155 <37.2 μmol/L
Methemoglobin Whole blood <1.0 % of total Hb 0.01 <0.01 Fraction of total Hb
Methionineb Plasma 0.1–0.6 mg/dL 67.1 6–40 μmol/L
Methsuximide (therapeutic) Serum, plasma 10–40 μg/mL 5.29 53–212 μmol/L
Methyldopa (therapeutic) Serum, plasma 1–5 μg/mL 4.73 5–24 μmol/L
Metoprolol (therapeutic) Serum, plasma 75–200 ng/mL 3.74 281–748 nmol/L
Mexthotrexate:
Toxic 24 h after dose Serum, plasma ≥10 μmol/L 1 ≥10 μmol/L
Toxic 48 h after dose Serum, plasma ≥1 μmol/L 1 ≥1 μmol/L
Toxic 72 h after dose Serum, plasma ≥0.1 μmol/L 1 ≥0.1 μmol/L
β2-Microglobulin Serum <2 μg/mL 85 <170 nmol/L
Monocytes (see complete blood count, white blood cell count)
Morphine (therapeutic) Serum, plasma 10–80 ng/mL 3.5 35–280 nmol/L
Muramidase (see lysozyme)
Mycophenolic acid (therapeutic) Serum, plasma 1.3–3.5 μg/mL 3.12 4–11 μmol/L
Naproxen (therapeutic) Plasma, serum >50 μg/mL 4.34 >217 μmol/L
Neutrophils (see complete blood count, white blood cell count)
Niacin (Vitamin B3, nicotinic acid) Plasma, serum 0.50–8.45 ug/mL 7.3 3.65–61.69 μmol/day
Nickel Whole blood 1.0–28.0 μg/L 17 17–476 nmol/L
Nicotine (smoker) Plasma 0.01–0.05 mg/L 6.16 0.062–0.308 μmol/L
Norepinephrineb Plasma 110–410 pg/mL 5.91 650–2423 nmol/L
Norepinephrineb Urine 15–80 μg/24 h 5.91 89–473 nmol/day
Nortriptyline (therapeutic) Serum, plasma 50–150 ng/mL 3.8 190–570 nmol/L
N-telopeptide (BCE, bone collagen equivalents):
Men Serum 5.4–24.2 nmol BCE/L 1 5.4–24.2 nmol BCE/L
Premenopausal women Serum 6.2–19.0 nmol BCE/L 1 6.2–19.0 nmol BCE/L
Ornithineb Plasma 0.4–1.4 mg/dL 75.8 30–106 μmol/L
Osmolalityb Serum 275–295 mOsm/kg H2O 1 275–295 mmol/kg H2O
Osmolality Urine 250–900 mOsm/kg H2O 1 250–900 mmol/kg H2O
Osteocalcinb Serum 3.0–13.0 ng/mL 1 3.0–13.0 μg/L
Oxalate Serum 1.0–2.4 mg/L 11.4 11–27 μmol/L
Oxazepam (therapeutic) Serum, plasma 0.2–1.4 μg/mL 3.49 0.7–54.9 μmol/L
Oxycodone (therapeutic) Plasma, serum 10–100 ng/mL 3.17 32–317 nmol/L
Oxygen, partial pressure (Po2) Arterial blood 80–100 mm Hg 1 80–100 mm Hg
Pantothenic acid (see vitamin B5)
Parathyroid hormone:
Intactb Serum 10–50 pg/mL 1 10–50 ng/L
N-terminal specificb Serum 8–24 pg/mL 1 8–24 ng/L
C-terminal (mid-molecule) Serum 0–340 pg/mL 1 0–340 ng/L
Pentobarbital (therapeutic) Serum, plasma 1–5 μg/mL 4.42 4.0–22 μmol/L
Pepsinogen Ib Serum 28–100 ng/mL 1 28–100 μg/L
pH (see blood gases)
Phenobarbital (therapeutic) Serum, plasma 15–40 μg/mL 4.31 65–172 μmol/L
Phenylalanineb Plasma 0.6–1.5 mg/dL 60.5 35–90 μmol/L
Phenytoin (therapeutic) Serum, plasma 10–20 μg/mL 3.96 40–79 μmol/L
Phosphatase, tartrate-resistant acid Serum 1.5–4.5 U/L 0.017 0.03–0.08 μkat/L
Phosphorus (inorganic)b Serum 2.3–4.7 mg/dL 0.3229 0.74–1.52 mmol/L
Phosphorus (inorganic)b Urine 0.4–1.3 g/24 h 32.29 12.9–42.0 mmol/day
Plasminogen Plasma 80–120 % 0.01 0.80–1.20 Fraction of 1.0
Plasminogen activator inhibitor activity Plasma 3–56 mIU/mL 1 3–56 IU/L
Platelet count (see complete blood count, platelet count)
Porphobilinogen deaminase Red blood cells >7.0 nmol/s/L 1 >7.0 nmol/(s L)
Potassium Plasma 3.5–5.0 mEq/L 1 3.5–5.0 mmol/L
Prealbumin—transthyretin Serum, plasma 18–45 mg/dL 0.01 0.18–0.45 g/L
Pregnanediol,b female:
Follicular phase Urine <2.6 mg/24 h 3.12 <8 μmol/day
Luteal phase Urine 2.3–10.6 mg/24 h 3.12 8–33 μmol/day
Pregnanediol,b male Urine 0–1.9 mg/24 h 3.12 0–5.9 μmol/day
Pregnanetriolb Urine <2.5 mg/24 h 2.97 <7.5 μmol/day
Primidone (therapeutic) Serum, plasma 12 May μg/mL 4.58 23–55 μmol/L
Procainamide (therapeutic) Serum, plasma 10 Apr μg/mL 4.23 17–42 μmol/L
Progesterone,b female:
Follicular phase Serum 0.1–0.7 ng/mL 3.18 0.5–2.2 nmol/L
Luteal phase Serum 2.0–25.0 ng/mL 3.18 6.4–79.5 nmol/L
Progesterone,b male Serum 0.13–0.97 ng/mL 3.18 0.4–3.1 nmol/L
Prolactin (nonlactating subject) Serum 1–25 ng/mL 1 1–25 μg/L
Prolineb Plasma 1.2–3.9 mg/dL 86.9 104–340 μmol/L
Propoxyphene (therapeutic) Serum 0.1–0.4 μg/mL 2.946 0.3–1.2 μmol/L
Propanolol (therapeutic) Serum, plasma 50–100 ng/mL 3.86 190–386 nmol/L
Protein (total)b Serum 6.0–8.0 g/dL 10 60–80 g/L
Protein C activity Plasma 70–140 % 0.01 0.70–1.40 Fraction of 1.0
Protein electrophoresis (serum protein electrophoresis [SPEP]), fraction of total protein:
Albumin Serum 52–65 % 0.01 0.52–0.65 Fraction of 1.0
α1-Globulin Serum 2.5–5.0 % 0.01 0.025–0.05 Fraction of 1.0
α2-Globulin Serum 7.0–13.0 % 0.01 0.07–0.13 Fraction of 1.0
β-Globulin Serum 8.0–14.0 % 0.01 0.08–0.14 Fraction of 1.0
γ-Globulin Serum 12.0–22.0 % 0.01 0.12–0.22 Fraction of 1.0
Protein electrophoresis (SPEP), concentration:
Albumin Serum 3.2–5.6 g/dL 10 32–56 g/L
α1-Globulin Serum 0.1–0.4 g/dL 10 1–10 g/L
α2-Globulin Serum 0.4–1.2 g/dL 10 4–12 g/L
β-Globulin Serum 0.5–1.1 g/dL 10 5–11 g/L
γ-Globulin Serum 0.5–1.6 g/dL 10 5–16 g/L
Protein S activity Plasma 70–140 % 0.01 0.70–1.40 Fraction of 1.0
Protein S free antigen Plasma 80–160 % 0.01 0.80–1.60 Fraction of 1.0
Prothrombin time (PT) Plasma 10–13 seconds 1 10–13 seconds
Protoporphyrin Red blood cells 15–50 μg/dL 0.0177 0.27–0.89 μmol/L
Prostate-specific antigen (PSA) Serum 0–4.0 ng/mL 1 0–4.0 μg/L
Pyridinium cross-links (deoxypyridinoline):
Male Urine 10.3–20 nmol/mmol creatinine 1 10.3–20 nmol/mmol creatinine
Premenopausal female Urine 15.3–33.6 nmol/mmol creatinine 1 15.3–33.6 nmol/mmol creatinine
Pyridoxine (see vitamin B6)
Pyruvate (as pyruvic acid) Whole blood 0.3–0.9 mg/dL 113.6 34–102 μmol/L
Quinidine (therapeutic) Serum, plasma 2.0–5.0 μg/mL 3.08 6.2–15.4 μmol/L
Red blood cell count (see complete blood count)
Red cell folate (see folate)
Renin (normal-sodium diet)b Plasma 1.1–4.1 ng/mL/h 1 1.1–4.1 ng/(mL h)
Reticulocyte countb Whole blood 25–75 103 μL−1 1 25–75 109 L−1
Reticulocyte countb (fraction) Whole blood 0.5–1.5 % of RBCs 0.01 0.005–0.015 Fraction of RBCs
Retinol (see vitamin A)
Rheumatoid factor Serum <30 IU/mL 1 <30 kIU/L
Riboflavin (see vitamin B2)
Salicylates (therapeutic) Serum, plasma 15–30 mg/dL 0.0724 1.08–2.17 mmol/L
Sedimentation rate (see erythrocyte sedimentation rate)
Selenium Whole blood 58–234 μg/L 0.0127 0.74–2.97 μmol/L
Serineb Plasma 0.7–2.0 mg/dL 95.2 65–193 μmol/L
Serotonin (5-hydroxytryptamine) Whole blood 50–200 ng/mL 0.00568 0.28–1.14 μmol/L
Sertraline (therapeutic) Serum or plasma 10–50 ng/mL 3.27 33–164 nmol/L
SPEP (see protein electrophoresis)
Sex hormone-binding globulinb Serum 0.5–1.5 μg/dL 34.7 17.4–52.1 nmol/L
Sirolimus (therapeutic) Whole blood 4–20 ng/mL 1.1 4–22 nmol/L
Sodiumb Plasma 136–142 mEq/L 1 136–142 mmol/L
Somatostatin Plasma <25 pg/mL 1 <25 ng/L
Somatomedin C (see insulin-like growth factor)
Strychnine (toxic) Whole blood >0.5 mg/L 2.99 >1.5 μmol/L
Substance P Plasma <240 pg/mL 1 <240 ng/L
Sulfhemoglobin Whole blood <1.0 % of total Hb 0.01 <0.010 Fraction of total Hb
Tacrolimus (therapeutic) Whole blood 3–20 ng/mL 1.24 4–25 nmol/L
Taurineb Plasma 0.3–2.1 mg/dL 80 24–168 μmol/L
Testosterone,b male Plasma, serum 300–1200 ng/dL 0.0347 10.4–41.6 nmol/L
Testosterone,b female Plasma, serum <85 ng/dL 0.0347 2.95 nmol/L
Theophylline (therapeutic) Plasma, serum 10–20 μg/mL 5.55 56–111 μmol/L
Thiamine (see vitamin B1)
Thiocyanate (nonsmoker) Plasma, serum 1–4 mg/L 17.2 17–69 μmol/L
Thiopental (therapeutic) Plasma, serum 1–5 μg/mL 4.13 4–21 μmol/L
Thioridazine (therapeutic) Plasma, serum 1.0–1.5 μg/mL 2.7 2.7–4.1 μmol/L
Thrombin time Plasma 16–24 seconds 1 16–24 seconds
Threonineb Plasma 0.9–2.5 mg/dL 84 75–210 μmol/L
Thyroglobulinb Serum 3–42 ng/mL 1 3–42 μg/L
Thyrotropin (thyroid-stimulating hormone, TSH)b Serum 0.5–5.0 μIU/mL 1 0.5–5.0 mU/L
Thyroxine, free (FT4)b Serum 0.9–2.3 ng/dL 12.87 12–30 pmol/L
Thyroxine, total (T4)b Serum 5.5–12.5 μg/dL 12.87 71–160 nmol/L
Thyroxine-binding globulin (TBG),b as T4 binding capacity Serum 10–26 μg/dL 12.9 129–335 nmol/L
Tissue plasminogen activator Plasma <0.04 IU/mL 1000 <40 IU/L
Tobramycin (therapeutic) Plasma, serum 5–10 μg/mL 2.14 10–21 μmol/L
Tocainide (therapeutic) Plasma, serum 4–10 μg/mL 5.2 21–52 μmol/L
α-Tocopherol (see vitamin E)
Topiramate (therapeutic) Serum, plasma 5–20 μg/mL 2.95 15–59 μmol/L
Transferrin (siderophilin)b Serum 200–380 mg/dL 0.01 2.0–3.8 g/L
Triglyceridesb Plasma, serum 10–190 mg/dL 0.01129 0.11–2.15 mmol/L
Triiodothyronine, free (FT3)b Serum 260–480 pg/dL 0.0154 4.0–7.4 pmol/L
Triiodothyronine, resin uptakeb Serum 25–35 % 0.01 0.25–0.35 Fraction of 1.0
Triiodothyronine, total (T3)b Serum 70–200 ng/dL 0.0154 1.08–3.14 nmol/L
Troponin I (cardiac) Serum 0–0.4 ng/mL 1 0–0.4 μg/L
Troponin T (cardiac) Serum 0–0.1 ng/mL 1 0–0.1 μg/L
Tryptophanb Plasma 0.5–1.5 mg/dL 48.97 25–73 μmol/L
Tyrosineb Plasma 0.4–1.6 mg/dL 55.19 20–90 μmol/L
Urea nitrogen (BUN)b Serum 8–23 mg/dL 0.0357 2.9–8.2 mmol/L
Uric acidb Serum 4.0–8.5 mg/dL 0.0595 0.24–0.51 mmol/L
Urobilinogenb Urine 0.05–2.5 mg/24 h 1.693 0.1–4.2 μmol/day
Valineb Plasma 1.7–3.7 mg/dL 85.5 145–315 μmol/L
Valproic acid (therapeutic) Plasma, serum 50–150 μg/mL 6.93 346–1040 μmol/L
Vancomycin (therapeutic) Plasma, serum 10–20 μg/mL 0.69 6.9–13.8 μmol/L
Vanillylmandelic acid (VMA)b Urine 2.1–7.6 mg/24 h 5.046 11–38 μmol/day
Vasoactive intestinal polypeptide Plasma <50 pg/mL 1 <50 ng/L
Verapamil (therapeutic) Plasma, serum 100–500 ng/mL 2.2 220–1100 nmol/L
Vitamin A (retinol)b Serum 30–80 μg/dL 0.0349 1.05–2.80 μmol/L
Vitamin B1 (thiamine) Whole blood 2.5–7.5 μg/dL 29.6 74–222 nmol/L
Vitamin B2 (riboflavin) Plasma, serum 4–24 μg/dL 26.6 106–638 nmol/L
Vitamin B5 (pantothenic acid) Whole blood 0.2–1.8 μg/mL 4.56 0.9–8.2 μmol/L
Vitamin B6 (pyridoxine) Plasma 5–30 ng/mL 4.046 20–121 nmol/L
Vitamin B12 (cyanocobalamin)b Serum 160–950 pg/mL 0.7378 118–701 pmol/L
Vitamin C (ascorbic acid) Plasma, serum 0.4–1.5 mg/dL 56.78 23–85 μmol/L
Vitamin D, 1,25-dihydroxyvitamin D Plasma, serum 16–65 pg/mL 2.6 42–169 pmol/L
Vitamin D, 25-hydroxyvitamin D Plasma, serum 14–60 ng/mL 2.496 35–150 nmol/L
Vitamin E (α-tocopherol)b Plasma, serum 0.5–1.8 mg/dL 23.22 12–42 μmol/L
Vitamin K Plasma, serum 0.13–1.19 ng/mL 2.22 0.29–2.64 nmol/L
von Willebrand factor (ranges vary according to blood type) Plasma 70–140 % 0.01 0.70–1.40 Fraction of 1.0
Warfarin (therapeutic) Plasma, serum 1.0–10 μg/mL 3.24 3.2–32.4 μmol/L
White blood cell countb Whole blood 4.5–11.0 103 μL−1 1 4.5–11.0 109 L−1
White blood cell, differential count (see complete blood count)
Xylose absorption test (25-g dose)b Whole blood >25 mg/dL mg/dL 0.06661 >1.7 mmol/L
Zidovudine (therapeutic) Plasma, serum 0.15–0.27 μg/mL 3.74 0.56–1.01 μmol/L
Zinc Serum 50–150 μg/dL 0.153 7.7–23.0 μmol/L

The sample type listed under Specimen in this table shows the reference interval for that specimen type. Thus, if the specimen for a test is listed as serum, the reference interval shown is for serum specimens. For many tests listed with serum as the specimen type, plasma is also acceptable, often with a similar reference interval.

The normal ranges listed here are included as a helpful guide and are by no means comprehensive. The listed reference, unless noted, pertains to adults. Laboratory results are method dependent and can have intralaboratory variation. Conversion factors are not affected by age-related differences. This table is compiled from data in the following sources: (1) Tietz NW, ed. Clinical Guide to Laboratory Tests. 3rd ed. Philadelphia, PA: WB Saunders Co; 1995; (2) Laposata M. SI Unit Conversion Guide. Boston, MA: NEJM Books; 1992; (3) American Medical Association Manual of Style: A Guide for Authors and Editors. 9th ed. Chicago, IL: AMA; 1998:486–503. Copyright 1998, American Medical Association; (4) Jacobs DS, DeMott WR, Oxley DK, eds. Jacobs & DeMott Laboratory Test Handbook with Key Word Index. 5th ed. Hudson, OH: Lexi-Comp Inc; 2001; (5) Henry JB, ed. Clinical Diagnosis and Management by Laboratory Methods. 20th ed. Philadelphia, PA: WB Saunders Co; 2001; (6) Kratz A, et al. Laboratory reference values. N Engl J Med. 2006;351:1548–1563; (7) Burtis CA, ed. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 5th ed. St. Louis, MO: Elsevier; 2012. This version of the table of reference ranges was reviewed and updated by Jessica Franco-Colon, PhD, and Kay Brooks.

aThe SI unit katal is the amount of enzyme generating 1 mol of product per second. Although provisionally recommended as the SI unit for enzymatic activity, it has not been universally accepted. It is suitable to maintain use of U/L in these circumstances (conversion factor 1.0).

bFor this analyte, there is sex or age dependence for the reference range. There may be several different normal ranges for different pediatric age groups. Consult your clinical laboratory for the local institution age-specific reference range. Pediatric reference values may also be found in Soldin SJ, Brugnara C, Wong EC, eds.; Hicks JM, editor emeritus. Pediatric References Intervals. 5th ed. (formerly Pediatric Reference Ranges). Washington, DC: AACC Press; 2005.

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Amino Acid 3-Letter Code 1-Letter Code
Alanine Ala A
Cysteine Cys C
Aspartic acid or aspartate Asp D
Glutamic acid or glutamate Glu E
Phenylalanine Phe F
Glycine Gly G
Histidine His H
Isoleucine Ile I
Lysine Lys K
Leucine Leu L
Methionine Met M
Asparagine Asn N
Proline Pro P
Glutamine Gln Q
Arginine Arg R
Serine Ser S
Threonine Thr T
Valine Val V
Tryptophan Trp W
Tyrosine Tyr Y

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