++
To detect the presence of schistocytes or blast cells in a peripheral blood smear. Schistocytes are fragmented red blood cells due to shearing forces in microarterioles lined or meshed with fibrin strands. They are found in patients with disseminated intravascular coagulation, throbotic thrombocytopenic purpura/haemolytic uremic syndrome, microangiopathic haemolytic anemia, uremia, and carcinoma. Turbulent blood flow due to congestive heart failure, artificial heart valves, or vavlular stenosis may cause schistocyte formation. Greater than 1% of forms or greater than two schistocytes per high-powered field suggest schistocytosis.
++
Peripheral blood smear blasts are circulating immature white blood cells. When elevated white blood cell count and circulating blasts are seen in addition to anemia and thrombocytopenia, acute leukemia is suspected. As leukemia blast cells build up in the bone marrow, they allow less room for production of healthy white blood cells, red blood cells, and platelets. Although the diagnosis of leukemia can usually be made from the peripheral smear, bone marrow examination (aspiration or needle biopsy) is routinely done for definitive diagnosis.
++
Two glass microscope slides, drop of blood, pipette, Wright stain, Giemsa stain, immersion oil, and microscope.
++
Agitate sample well, by inversion of tube or mechanical rocker.
Place a 2- to 3-mm drop of whole blood ¼ in from the right edge of a 1 × 3 in slide using a wooden applicator stick.
Place the slide on a flat surface and hold securely.
Grasp a second slide (spreader slide) in the right hand between thumb and forefinger.
Place the spreader slide onto the lower slide in front of the blood drop, and pull the slide back until it touches the drop.
Allow the blood to spread by capillary action almost to the edges to fht lower slide.
Push the spreader slide forward at a 30-degree angle, using a rapid even motion. The weight of the spreader slide should be the only weight applied. The drop of blood must be spread within seconds or the cell distribution will be uneven.
Allow to air dry.
+++
Wright Stain of Peripheral Smear
++
Completely cover peripheral smear with Wright stain using a pipette. The stain layer should be ⅛ in thick.
Wait for 2 minutes.
Cover with equal amount of Giemsa solution.
Blow gently on the slide to mix solutions.
Allow to stand for 4 minutes.
Wash slide for 30 seconds with distilled water.
Allow to air dry
View smear with oil emersion at high (100×) power.
++
++