Immunoglobulin G (IgG) is the most abundant immunoglobulin in serum and is predominately involved in the secondary immune response. The IgG subclasses are designated 1, 2, 3 and 4 based on their relative prevalence in serum. The sensitive quantitative measurement of total Armenian hamster IgG antigen in serum, plasma, hybridoma cell supernatants, ascites or other biological fluid samples is easily performed with this 96 well strip format ELISA kit. The assay does not distinguish IgG subclasses. The kit does not cross react significantly with human, monkey, mouse, rat, dog, pig or rabbit IgG. The concentration of IgG in normal Armenian hamster serum ranges from 5 to 12 mg/ml. The assay measures Armenian hamster IgG in the 2-1,000 ng/ml range. Samples giving Armenian hamster IgG levels above 1,000 ng/ml should be diluted in blocking buffer before use. A 1:100,000 to 1:1,000,000 dilution for serum is suggested for best results. Armenian hamster IgG will bind to the affinity purified capture antibody coated on the microtiter plate. After appropriate washing steps, horseradish peroxidase labeled polyclonal anti-Armenian hamster IgG primary antibody binds to the captured protein. Excess antibody is washed away and TMB substrate is used for color development at 450nm. A standard calibration curve is prepared along with the samples to be measured using dilutions of Armenian hamster IgG. Color development is directly proportional to the concentration of total IgG in the samples. All reagents and standards are provided in these ELISA kits.