Figure 1.

Average DNA yield obtained using the four commercial kits as influenced by fecal specimen weights. DNA was extracted from 200, 100, 50, 25, and 10 mg of human fecal specimens (n = 45/kit), using Mobio Ultra Clean^® Fecal DNA Isolation Kit (M), QIAamp^® DNA Stool Mini Kit (Q), FastDNA^® SPIN Kit (FSp), and FastDNA^® SPIN Kit for Soil (FSo). Values for DNA yield were normalized based on the dry weight of the respective fecal specimen. Means with different letter designation are significantly different (comparisons within each extraction kit; P < 0.05).