Comparison of conventional tube test and gel microcolumn assay for IgG antibodies against blood group antigens

Objective To compare gel microcolumn assay and conventional tube test for IgG anti-A (B) titration. Methods Fifty-three blood samples of “O” group pregnant women, whose husbands were of non “O” group, were detected simultaneously by the conventional tube test and gel microcolumn assay. The results were analyzed using paired “t ” test. Results IgG anti-A (B) titration in gel microcolumn assay showed significantly higher titres (mean 3.56-fold) than that in conventional tube test in all samples studied (P 0.001). The coefficient of correlation between the two methods for IgG anti-A (B) was 0.829 (P 0.001). In addition, IgG anti-A (B) titres in 398 cases of “O” group pregnant women by gel microcolumn assay were significantly higher proportion above 1:64 than that by conventional tube test. Conclusion The gel microcolumn assay is superior to the conventional tube test. It has the further advantage of standardization of the test, shorter incubation time, and no washing procedure. The critical titre for anti-A (B) should be established in view of the high sensitivity of the gel microcolumn assay.