Igh-6b Expression in BALB.nude Mice

Mice that differ at Igh loci and the reagents that permit resolution of such distinctions are powerful genetic tools for studying B cell heterogencity. In this report, IgM-allotype-specific ELISA revealed that two of three sources of mice designated as BALB.nude express the Igh-6b (IgMb) allotype characteristic if C57BL mice. This observation serves to warn investigators that not all strains of mice designated BALB.nude express the Igh-6a (IgMa) allotype.