Agarose gel electrophoresis is a well established technique routinely used in clinical laboratories for screening protein abnormalities in various biological fluids (serum, urine, CSF). It is based on the principles of zone electrophoresis. Electrophoretograms are evaluated visually for the presence of quantitatively or qualitatively abnormal protein bands. The technique is used for electrophoresis of serum, urine, CSF proteins, enzymes (ALP, LDH and CK), lipoproteins and hemoglobin. Serum protein electrophoresis (SPE) is a very commonly used analytical method in clinical chemistry. Changes in the relative concentration of fractions allow easy recognition of pathological disorders associated with nephrotic syndrome, inflammatory reaction and hepatic diseases. SPE is a screening test for detecting the M component (MC). Immunofixation (IFE) with use of specific antisera allows detection of the type of MC. SPE is also a method for the quantification of MC and monitoring of disease that is essential for clinical evaluation and follow-up of patients with plasma cell disorders.