A robust and cost-effective method for DNA isolation from Satureja species (Lamiaceae)

Aromatic species of the genus Satureja are rich in secondary metabolites that interfere with DNA isolation procedures. Four protocols based on the standard CTDNA extraction protocol of Doyle and Doyle (1987) were tested in six savory taxa. The polyphenol adsorbents activated charcoal and/or polyvinylpyrrolidone 10 were employed in three procedures (B, C and D); for the elimination of polysaccharides, 4M NaCl was applied in the latter two. The highest DNA yield was obtained with Protocol D and averaged 1420.7?398.3 ?g DNA/g of dry leaf tissue. Optimal values of the absorbance ratio 260/280 of all DNA solutions revealed the absence or only negligible contamination by proteins. Contamination by polysaccharides inferred from the absorbance ratio 260/230 showed that Protocol C provided the least contaminated material (average of 1.7?0.4). Enzymatic reactions of DNA solutions obtained by Protocol D showed amplification of both loci in all individuals. In conclusion, Protocol D is suitable for the isolation of high quantities of pure DNA from Satureja spp.