This reagents are designed for use as a direct immunofluorescence reagent in the identification and enumeration of cells which express Lambda and Kappa immunoglobulin Light Chains by Flow Cytometry (FC). Antibodies to Lambda and Kappa Light Chains are useful for the identification of clonal excess in B-cell lymphoproliferative disorderstogether with a panel of other antibodies.

Anti-Lambda Light Chains reacts with free Lambda Chains as well as Lambda Chains in intact immunoglobulin molecules. Anti-Kappa Light Chains reacts with free Kappa chains as well as Kappa chains in intact immunoglobulin molecules.

Human lymphocytes may be classified in three main populations according to their biological function and their cell surface antigenexpression: T lymphocytes, B lymphocytes and natural killer cells (NK). B lymphocytes are the producers of antibodies and mediate humoral immunity particularly effective against toxins, whole bacteria, and free viruses.

Most B cells, with the exception of pre-B progenitors, pre B cells, and mature plasma cells, express immunoglobulin on their surface. Each cell expresses only one Light Chain type. In normal peripheral blood and lymph nodes, there is a mixture of Kappa positive and Lambda positive cells, with two-thirds of the cells expressing Kappa and one-third expressing Lambda. Since lymphoid neoplasms are usually clonal expansions of a single cell, malignant cells uniformly express the same Light Chain isotype. Neoplastic B cell lymphoprolipherative disorders can frequently be suspected on the basis of the demonstration of a marker predominance of cells expressing a single Light Chain type.