The qualitative immunoenzymatic determination of IgM-class antibodies against Rubella Virus is based on the ELISA (Enzymelinked
Immunosorbent Assay) technique. The Rubella Virus IgM ELISA is an IgM µ-capture ELISA. The plates are coated with antihuman
IgM. After washing the wells to remove all unbound sample material horseradish peroxidase labelled Rubella virus antigen
conjugate is added. This conjugate binds to the captured Rubella-specific antibodies. The immune complex formed by the bound
conjugate is visualized with Tetramethylbenzidine (TMB) substrate which gives a blue reaction product. The intensity of this product
is proportional to the amount of Rubella-specific IgM antibodies in the specimen. Sulfuric acid is added to stop the reaction. This
produces a yellow endpoint colour. Absorbance at 450 nm is read using an ELISA microwell plate reader.