Figure 1. Average concentration of DNA yielded by each mg of tissue used. On average, 21.7 ng/μl (standard error=3.63 ng/μl) of DNA was yielded per 1 mg of retinal tissue used. As for the iris, on average, 7.42 ng/μl (standard error=2.01 ng/μl) of DNA was yielded per 1 mg of iris tissue used. The difference is statistically significant (p<0.01).