There are several types of contaminations that can be acquired during the DNA extraction protocols, depending on the origin of the biological sample [12,13]. Phenolics and other secondary compounds cause damage of the DNA and/or inhibit enzymatic reactions. The quality of the samples evaluated in terms of RNA/protein and chaotropic salt contamination was respectively, 1.88 ± 0.04 and 1.83 ± 0.12
(mean ± SE) (Table 1), being all samples analyzed around the optimal value, for both quality standards.
These minor levels of salt, protein or RNA contamination prevent interference in downstream
molecular biology procedures and so, it is very important to maintain its levels to a minimum.
Riemann et al. [17] suggested that quantity and quality of the isolated DNAs were slightly higher with
manual extraction than automatic extraction methods. In our experience we notice that the automatic
extraction is more efficient regarding the quality of genomic DNA, which is very important to
downstream molecular procedures