TABLE 3.

A₂₆₀/A₂₈₀ Ratios of Four Kits (by gender)

Kit/gender	Mean ratio A260/A280 (±SD)	Possible confounding factors
Qv Woman	3.33 ± 0.12	carrier RNA, sodium azide
Qv Man	3.39 ± 0.06
Qm Woman	2.53 ± 0.34	carrier RNA, sodium azide
Qm Man	2.48 ± 0.64
iG Woman	1.19 ± 0.60	residual chemicals (phenol, guanidine) or other reagent used in the extraction protocol
iG Man	1.64 ± 0.19
Ab Woman	0.93 ± 0.39	residual chemicals (phenol, guanidine) or other reagent used in the extraction protocol and/or a very low DNA concentration
Ab Man	0.96 ± 0.16

Pure DNA has a A₂₆₀/A₂₈₀ ratio of 1.8.