Northern blot analysis of murine Cyp21a1 mRNA. Total RNA from murine adrenals was probed with a full-length DIG-labeled Cyp21-cDNA. Immunological detection of the probe was performed using the DIG luminescent detection kit (Boehringer). H-2^b/H-2^b, Homozygous wild-type; H-2^b/H-2^aw18, heterozygous wild-type; H-2^aw18/H-2^aw18, homozygous.