Figure 1.

Genotyping mice by Northern blotting and PCR. (A) Autoradiograph of Northern blots hybridized with a fibrillin-1 probe. RNA (20 μg) extracted from lung was electrophoresed, and the blots were hybridized with a 3′-end [³²P]fibrillin probe (8,401–8,601 bp). The size of the wild-type fibrillin-1 gene transcript is 9.5 kb, whereas the transcript of the mutated gene is 12.5 kb. (B) PCR for genotyping mice bearing wild-type or disrupted IL-4 genes. Tail-extracted genomic DNA was amplified by using forward and reverse primers as described in Material and Methods. The disrupted allele yields a PCR product of 1,351 bp, whereas the wild-type allele yields a product of 175 bp.