A sensitive ELISA for the detection of bovine crude heparin in porcine heparin.

Heparin is an effective anticoagulant drug which has been purified for decades from bovine or porcine tissues. However, with the emergence of BSE, heparin purification is today restricted to porcine intestinal mucosa. To control the origin of crude heparins, polyclonal antibodies were raised against bovine contaminants. These antibodies were used to develop one sandwich and two competitive indirect ELISAs. Optimal results were obtained with competitive indirect ELISA, using bovine crude heparin for the coating and anti-bovine crude heparin as a detector antibody. The detection limit of the assay was 1 ppm of bovine crude heparin in a porcine heparin. Taking into account the variability of the background obtained for 10 crude and 9 pure porcine heparins from known origin, the detection level was 5 ppm. Ovine and caprine crude heparins cross-reacted slightly (6-17 ppm).