Optimization and Assessment of Different DNA Extraction Protocols in Cowpea (Vigna unguiculata L. Walp.)

Abstract

The first and the most essential step in any genetic analysis is the extraction of good quality DNA. In this study, comparison of five different protocols of isolating total genomic DNA from Cowpea plant (Vigna unguiculata) was carried out. A total of 10 varieties of cowpea (V. unguiculata) were collected from IITA and planted in pots in a screenhouse in the Department of Botany, University of Ibadan, Nigeria. After two weeks, DNA was extracted from their leaves using five different DNA extraction methods namely; CTAB protocol, Modified Dellaporta protocol, DNAzol kit, ZR MiniPrep Kit and Epicenter kit (for Blood) and were compared and analysed using nanodrop spectrophotometer and agarose gel electrophoresis. The results from the spectrophotometer showed that CTAB protocol yielded the highest concentration of DNA with a mean value of 2136.51ng/µl, followed by Dellaporta 1707.77ng/µl and least was ZR MiniPrep kit with concentration of 103.64ng/µl. Assessing the purity of DNA, Dellaporta protocol demonstrated DNA purity with mean value of 2.031 indicating slight RNA contamination followed by CTAB protocol 1.966 and the least was ZR MiniPrep kit at 1.263. The results showed that CTAB protocol was the best for further analysis as it provided good DNA quality and quantity.