TABLE 2.

Comparison of methods of extracting DNA from diluted cultures of C. albicans

Method	Reference or source	Sensitivity (cells/ml)a	Time (h)	Ease of use and recovery
Zymolyase, SDS, proteinase K, phenol	Buchman et al. (4)	10 (1) or inhibition (1)	2	Handy, phenol, two enzymatic steps, good recovery or total inhibition
Zymolyase, proteinase K, phenol, RNase	Holm et al. (9)	10 (1) and 102 (1)	4	Tedious, phenol, three enzymatic steps, good recovery
Glass beads, phenol	Sanglard et al. (19)	102 (2)	0.75	Handy, phenol, medium recovery
Zymolyase, proteinase K, lysing solution, RNase	Sanglard et al. (20)	106 (2)	2	Handy, no phenol, three enzymatic steps, low recovery
Zymolyase, silica beads	Boom et al. (3)	102 (2)	2.5	Handy, no phenol, one enzymatic step, medium recovery, some inhibition
Zymolyase, proteinase K, silica membrane	Qiagen	102 (1)	2	Very handy, no phenol, two enzymatic steps, medium recovery
Zymolyase, proteinase K, silica membrane	Macherey & Nagel	10 (3)	2	Very handy, no phenol, two enzymatic steps, good recovery
Proteinase K, silica membraneb	Qiagen (modified protocol)	10 (23)	1.5	Simple, rapid, no phenol, one enzymatic step, good recovery

^aTenfold serial dilutions of an overnight C. albicans culture in water were obtained as described in Materials and Methods, and cell quantification was performed as explained in Materials and Methods. A 10-μl aliquot of the DNA extracted from each dilution was used for PCR amplification. A 10-μl aliquot of the PCR product was used for detection by agarose gel electrophoresis with EtBr staining. The sensitivity was defined as the highest dilution which produced a visible band by EtBr staining after agarose gel electrophoresis with the SAP primers and the PCR protocol described in the text. The number of separate experiments is indicated in parentheses. 

^bThis method was adopted for the present study.