Sestavení Kompetitivní Enzymové Imunoanalýzy Pro Stanovení Α-Laktalbuminu a Β-Laktoglobulinů Kravského Mléka

Polyclonal antibodies were raised against three immunogens- a-lactalbumin (LA), -lactoglobulin A (LGA) and B (LGB). Using these antibodies the procedures of an indirect competitive enzyme immunoassay (ELISA) were constructed, optimized a nd characterized for determination of indi vidual immunogens. It was found that ELISA of LA is very specific without any inter­ ferences of other whey proteins. However, in ELlSAs of both lactoglobulins A and B were demonstrated very high interferences of the other genetic varian t (cross-reactivities 20-280% depending on antibody and immu nogen). An excellent sensitivity of ELISA for all proteins (detection limits for LA, LGA and LGB were 13, 0.4 and 54 ng/ml, respectively) makes it possible to analyze milk samples diluted more than 1000 times. Average values of variation coefficient were in the range 16-27%. A compari­ son of whey protein determinations in raw cow's milk by ELISA and by capillary electrophoresis resulted in the best similarit y in results of LA concentration. The decrease of LA, LGA and LGB concen trations was detected by using capillary electrophoresis for an analysis of whey from heat-treated milk, while ELISA of the same milk sample showed the increase of LGB immunoreac­ tivity to 700%.