Table 1.

Guanidine thiocyanate (with alcohol) outperforms guanidine hydrochloride for extraction of DNA from dried blood spots

	3M GuSCN			3M GHCl
Alcohol	0%	16.7% ISOH	16.7% ETOH	0%	16.7% ISOH	16.7% ETOH
Average Ct for Pf 18S rDNA (± SD)	Undetectable	29.2 (± .1)	29.3 (± .2)	Undetectable	Undetectable	Undetectable
Average Ct for human actin (± SD)	28.8 (± .2)	27.3 (± .3)	27.6 (± .3)	29.6 (± .4)	Undetectable	Undetectable

Experiments done with samples at parasite density of 2000 parasites/mL

Pf, Plasmodium falciparum; GuSCN, guanidine thiocyanate; GHCl, guanidine hydrochloride; ISOH, isopropanol; ETOH, ethanol; SD, standard deviation; Ct, cycle threshold