Sestavení kompetitivní enzymové imunoanalýzy pro stanovení α-laktalbuminu a β-laktoglobulinů kravského mléka
L. Karasova, P. Rauch, L. Fukalhttps://doi.org/10.17221/10014-CJFSCitation:Karasova L., Rauch P., Fukal L. (1999): Sestavení kompetitivní enzymové imunoanalýzy pro stanovení α-laktalbuminu a β-laktoglobulinů kravského mléka. Czech J. Food Sci., 17: 5-14.
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%.Keywords:
α-lactalbumin; β-lactoglobulin; whey proteins; ELISA