Production and Assessment of Goat Antihuman Globulin Reagent

Chung, Jae Lim; Yong, Dong Eun; Kim, Mun Jeong; Kim, Hyun Ok; Cho, Young Sik

Abstract

BACKGROUND
Since the 1960 s rabbit antihuman globulin reagent has been used widely. Recently most conjugate of enzyme immunoassay is produced from goat, and precise purification method is developed. Therefore we evaluated the commercial value of the goat antihuman globulin as a blood bank test reagent.
METHODS
The human IgG was purified by protein-A gel, and injected into goat. The goat antihuman globulin was coupled by CNBr activated sepharose 4B-gel and purified by 0.2M glycine elution buffer. For verification of this reagent, commercial reagents(Ortho rabbit reagent & DiaMed Gel test) were used.
RESULTS
The minimal concentration for detecting antibody of goat reagent was 9 ng/mL. The results of direct antiglobulin tests, with 400 samples collected from donated blood in CPDA-1, were all negative(false positive rate: 0%). With 613 samples collected from inpatients of Severance Hospital, the results were positive in 35 patients(positive rate:5.7%), and those results were in complete agreement with commercial reagent(concordance rate: Goat vs. Ortho :99.8%, Goat vs. DiaMed :98.4%). And with 30 samples of artificially prepared complement-coated RBC, the results were all negative. Indirect antiglobulin test showed higher agglutination score than commercial reagents.
CONCLUSIONS
Goat reagent showed high sensitivity and specificity in comparison with rabbit reagent. Because false positive reaction was not observed in negative control samples, the heterophil agglutinin reaction, which was the major problem when the reagent was initially developed, might be excluded. In conclusion, goat reagent seems to be more economical than rabbit reagent because the former can be obtained in a large quantity and of high potency.