Different diseases and conditions result in increasing of antibody producing cell number. These cells produce a large number of Immunoglobulins ( also known as Antibodies: are proteins involved in body protection against foreign bodies and diseases using various mechanisms ).The concentration of serum immunoglobulins provide information about the statue of the humoral immune system in the body, low concentration indicates some immunodeficiencies and high immunoglobulin concentration appears in different diseases and conditions such as inflammatory diseases, hematological diseases, infections, and malignancies.There are many methods and techniques to determine the concentration of these proteins which are routinely used in immunological or serological laboratories, using serum sample. This could be achieved by BN II ( Behring Nephelometer II: a machine is used at KAUH which depends on formation of ¬†immunocomplexes and light scattering )Immunoglobulins have different types: IgG, IgM, IgA, IgD and IgE each of them composed of essential primary components identical heavy chains and light chains.In addition, to detection and identification of presence or absence of abnormal Ig’s in serum, urine or spinal fluid Immunofixation serum test is performed.Immunofixation consists of two main steps: Electrophoresis and ImmunofixationElectrophoresis is the movement of the charged particles in an electric field, the migration of a particle depends on its size, charge and the nature of support medium.The major proteins patterns of the usual bands seen in Electrophoresis of serum is: albumin, alpha 1, alpha 2, beta, and gammaIt is screening procedure, used for detection of abnormalities in major serum proteins. The evaluation is done visually by observing the bands and patterns, the changes in normal proteins concentration or presence of abnormal proteins can be detected.Any alteration affects the usual appearance of the patterns may represent disease and can help in the diagnosis.Immunofixation is used as a further step to determine which type of immunoglobulin is present and to distinguish monoclonal from polyclonal or oligoclonal.It is also used in confirmation of the presence of myoglobin in the urine after damage of skeletal muscle.It can determine and identify presence of heavy chain ( IgM , IgG or IgA ) and light chains ( Kappa or lambda) the picture showing a monoclonal band of IgM Kappa-type using the same principle of the first step ( electrophoresis ) these separated proteins then ¬†are incubated with specific antisera against IgG, IgA, IgM, IgD and IgE heavy chains and kappa, and lambda light chains.Electrophoresis is performed on the urine sample to detects proteins in tubular and glomerular of a patient with renal disease. Due to the small size of light chains, they are excreted into urine.Some Immunoglobulins are detected in other fluids rather than serum such as CSF in cases of disorders in the central nervous system. Synthesis of immunoglobulins occurs in CSF. Oligobands are detected in this case associated with multiple sclerosis and another disease that their Abs cannot be detected in the serum.All these results primarily must be correlated with BN II results