Specificity studies on anti-histone H1 antibodies obtained by different immunization methods

Antibodies were elicited against chromatographically purified histone H l subfractions or against their complexes with RNA and their specificity studied by enzyme-linked immunosorbent assay. The results show that complexing of the pure protein with RNA (i) does not lead to any significant increase in the antibody titer and (ii) results in obtaining antibodies predominantly against the common antigenic determinants present in the HI histone class. On the other hand, using pure histone fractions for immunization gives rise to antibody populations reacting mainly with the subfraction-specific determinants on the histone molecule. In view of these results the literature data should be interpreted with caution.