Lab Test

Kappa Lambda Light Chain RNA Detection by in-situ Hybridization

Specimen Collection Criteria

Collect: Paraffin-embedded tissue. A paraffin block must be submitted. (Slides or paraffin shavings are not acceptable.) Submit formalin-fixed, paraffin-embedded block with corresponding H&E slide. Tissue should be well fixed and well processed. Average tissue size 5 mm2.

  • RNA will be assessed for quality during the process of hybridization. If it is deemed unacceptable, testing will be cancelled with client notification.
  • Specimen must be accompanied by a completed requisition and must contain the patient name, date of birth, collection date, ordering physician, and source of specimen.

Physician Office/Drawsite Specimen Preparation

Maintain paraffin-embedded tissue or slides at room temperature (20-25°C or 68-77°F) until transport.

Preparation for Courier Transport

Transport: Paraffin-embedded tissue, at room temperature (20-26°C or 68-78.8°F).

Rejection Criteria

  • Tissue in fixatives other than 10% formalin or zinc formalin.
  • Decalcified tissue.
  • Improper labeling, inadequate information. 


Monday - Friday.
Results available in 10 business days.

Reference Range

An interpretive report will be provided.

Test Methodology

Kappa and Lambda Light Chain Immunoglobulin messenger RNA (mRNA) can be detected in tissue sections by a hybridization reaction with oligonucleotide probes. The test utilizes horseradish peroxidase-conjugated detection chemistry to localize fluorescein-labeled oligonucleotide probes. Following the hybridization of fluorescein-labeled probes to target sequences in the tissue, a stringent wash solution containing a blocking agent is used to remove excess bound proge and to block nonspecific binding sites on the tissue that may otherwise react with the detection reagents. The fluorescein label is amplified via a mouse antifluorescein isothiocyanate (FITC) linker antibody. This can be visualized with HRP conjugated anti mouse antibody and a colorimetric reaction or the enzyme conjugate with its substrate. This reaction results in the deposition of an insoluble brown product at the site of hybridization.


An interpretive report will be provided.

Clinical Utility

Each test contains a cocktail of oligonucleotide probes. The intended target is the kappa light chain immunoglobulin messenger RNA (mRNA) in the cytoplasm of immunoblastic cells, plasma cells and plasmacytoid cells. Assessing the light chain immunoglobulin restriction is important in malignant lymphoma diagnosis. The relationship between monoclonal B-cell proliferation and light chain mRNA restriction aid in the distinction between neoplastic and reactive lymphoid proliferations and the evaluation of multiple myeloma, plasmacytoma, lymphomas with plasmacytoid features, immunoblastic lymphomas, and reactive plasma cell proliferations.

CPT Code

88364, 88365.

Last Updated


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This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.