Maxim's Cambridge biotech HIV-1 Serum Western Blot Kit is an FDA Approved in-vitro qualitative assay for the detection and identification of antibodies to Human Immunodeficiency Virus Type 1 (HIV-1) contained in human serum or plasma. It is intended for use with persons of unknown risks as an additional specific test on human serum or plasma specimens found to be repeatedly reactive using a screening procedure, such as an Enzyme-Linked Immunosorbent Assay (ELISA).