An enzyme immunoassay for the detection of IgM antibodies to herpes simplex virus type 1 (HSV-1) in serum. Herpes Simplex Virus is a common pathogen and its primary infection is usually asymptomatic. There are two immunologically distinct types of HSV: Type 1 and Type 2. HSV-1 is generally associated with oral infection and lesions above the waist, and HSV-2 is associated with genital infections and lesions below the waist. Clinical cases primarily are (1) eczema herpeticum with eczematous skin changes with numerous lesions, (2) gingivo-stomatitis, and (3) herpes sepsis, almost only found in premature newborn infants. The HSV-1 IgM ELISA is an accurate serologic method to detect HSV-1 IgM specific-antibody in serum samples.Purified HSV-1 antigen is coated on the surface of microwells. Diluted patient serum is added to the wells, and the HSV-1 IgM- specific antibody, if present, binds to the antigen. All unbound materials are washed away. HRP-conjugate is added, which binds to the antibody-antigen complex. Excess HRP-conjugate is washed off and a solution of TMB Reagent is added. The enzyme conjugate catalytic reaction is stopped at a specific time. The intensity of the color generated is proportional to the amount of HSV-1 IgM-specific antibody in the sample. The results are read by a microwell reader compared in a parallel manner with calibrator and controls.