DETECTION OF HUMAN SEMINAL GAMMA-GLUTAMYL-TRANSPEPTIDASE IN STAINS USING SANDWICH ELISA

A sensitive and specific sandwich ELISA for human seminar gamma-glutam yl transpeptidase (gamma-GTP) was developed using a combination of mon oclonal antibodies, SG1 and SG3, which we produced. For semen identifi cation in forensic samples, we modified the assay so as to be more sen sitive and to establish efficient extracting conditions. After testing the extracting abilities of several detergents, CHAPS and deoxy-BIGCH AP were chosen as the solubilizer. Polystyrene beads coated with SG1 w ere incubated with samples extracted by the detergents, and further wi th biotinylated SG3, followed by peroxidase-labeled streptavidin. gamm a-GTP was detected only in seminal samples. The sensitivity of this as say was 0.01 ng/ml of seminal gamma-GTP equivalent to 10(7) times dilu ted semen, which was ten times as compared with the previous plate ass ay. No significant seminal gamma-GTP was detected in other biological stains such as blood, saliva and vaginal smear. The extract of a 500 f old diluted seminal stain, 8 months old, showed the detection limit. S eminal gamma-GTP was detectable even in 14-year-old stains. (C) 1998 E lsevier Science Ireland Ltd.