A METHOD FOR STUDYING GENETICS OF THE PREDATORY MITE PHYTOSEIULUS PERSIMILIS

Abstract

Two DNA extraction and purification procedures for single mite analysis, organic (phenol-chloroform) method and the Chelex® -100 DNA extraction procedure, have been compared concerning extraction efficiency, DNA purity and DNA suitability for amplification. Phenol-chloroform extraction takes a relatively long period of time (5 days) and involves the use of toxic and hazardous chemical reagents but it produces consistent results. Chelex is a chelating resin that has a high affinity for polyvalent metal ions, Singer-Sam et al. postulated that boiling a sample in the presence of chelex prevents the degradation of DNA. Both method were evaluated to extract DNA from single frozen mite or individual recovery after treatment for microscopic analysis. The modify Chelex technique presents three clear advantages over the phenol-chloroform in order to increases the magnitude of DNA amplification and involves less time and work (2hrs only).