A highly specific enzyme linked immunosorbent assay (ELISA) for the detection of lactate dehydrogenase-1 (LD-1) has been developed. A competition assay is described with polyclonal antibody to LD-1 passively adsorbed on an ELISA 96-well plate, with non-labelled and labelled LD-1 antigen competing. The LD-1 antigen is conjugated to alkaline phosphatase (ALP) using the one step glutaraldehyde method. A linear range of 10-4000 U/L was obtained, and cross-reactivity was only observed with LD-2. It was possible to eliminate this cross-reactivity by carrying out the final incubation step at 65 degrees C. The developed assay was applied to the analysis of spiked serum and plasma samples and the recoveries obtained were acceptable.