Fig. 1

Agarose gel electrophoresis (2.5%) of the fragment comprising part of the intron 2 region and part of the exon 2 region of SOD1. The bands indicate fragments of approximately 218 bp that were previously treated with the restriction enzyme HpyCH₄ III, and which showed no restriction polymorphisms. LD: DNA ladder (100 bp). Keratoconic blood samples (013, 014, 015, 02, 05, 012, 017, and 106) and cornea (065, 088, 070, 052, 051, 099, 114, and 140). C1, C2, and C3: positive reaction controls (ABO blood group gene fragment, which contains the restriction sites for the HpyCH₄ III enzyme)