Free light chain monoclonal antibodies are essential in diagnostics due to their high specificity and sensitivity, enabling precise detection of kappa and lambda free light chains, which are critical biomarkers for conditions like multiple myeloma and AL amyloidosis. These antibodies facilitate early diagnosis, accurate disease monitoring, and risk stratification by allowing the detection of subtle changes in FLC levels. Used widely in immunoassays such as ELISAs, nephelometry, and turbidimetry, monoclonal antibodies ensure consistency and reliability in clinical results, making them indispensable tools in the diagnosis and management of plasma cell disorders.