Immunoglobulin<unk><unk> s that are circulating in serum in a<unk>  (unbound) state are called<unk><unk><unk> s (FLCs).<unk>  of the serum level of FLCs became practical as a clinical blood test in recent decades. These tests are used as an aid in the diagnosis and monitoring of multiple myeloma and related disorders. There are two types of immunoglobulin<unk><unk>  produced in humans, designated by the Greek letters kappa (κ) and lambda (λ). Comparing the ratio of κ FLCs to λ FLCs in a person's serum against reference ranges indicates whether that person may have a plasma cell tumour such as multiple myeloma or AL amyloidosis.
Serum free light-chain measurement
Bone biopsy
Serum protein electrophoresis
Renal biopsy
Skin biopsy
Scanning laser ophthalmoscopy
Retinoscopy
Urine protein/creatinine ratio