RT Book, Section A1 MA, Lichtman A1 MS, Shafer A1 RE, Felgar A1 N, Wang SR Print(0) ID 1138038894 T1 In Situ Hybridization Methods T2 Lichtman's Atlas of Hematology 2016 YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9780071602679 LK accessmedicine.mhmedical.com/content.aspx?aid=1138038894 RD 2024/03/28 AB Graphic Jump LocationView Full Size||Download Slide (.ppt)X.D.001In situ hybridization for light chains in a case of myeloma. Marrow. In situ hybridization for either kappa or lambda immunoglobulin light chain RNA was performed using biotin-labeled oligonucleotide probes, followed by a streptavidin-alkaline phosphatase detections system and colored substrate formation. In the left panel, the color reaction in the cytoplasm confirms that plasma cells express monoclonal kappa light chain as reflected in the intense cytoplasmic dark blue to black staining. In the right panel there is no reactivity of plasma cells with the lambda specific probe (absence of cytoplasmic staining). In a case in which plasma cells are synthesizing lambda light chains, the lambda reaction would be positive (cytoplasm dark blue to black) and the kappa reaction negative. This result is indicative of a clone of neoplastic plasma cells synthesizing a monoclonal kappa light chain.