Preliminary Attempts to Purify Genomic and Mitochondrial DNA from a Freshwater Sponge

Abstract

This project was intended to be a pair of preliminary experiments from which more detailed and specific experiments could be expanded. There were two procedures used in carrying out this study involving the isolation of DNA from a freshwater sponge. First, genomic DNA was isolated and purified. This genomic DNA was digested with the restriction endonuclease EcoR1 and then analyzed using agarose gel electrophoresis. The results showed an accumulation of the sponge DNA in one major band roughly slightly larger than the 21226 bp band generated by EcoR1 digestion of X-phage DNA. The second part of this experiment was an attempt to isolate mitochondrial DNA (mtDNA) from the sponge. Prior to isolation a succinate-INT reductase (SIR) assay was done on fractionated sponge tissue. SIR activity is due to succinate dehydrogenase, an enzyme that is specific to mitochondria. The results of this assay confirmed that the fractionation procedure used in the purification procedure yielded a fraction rich in mtDNA. A simple and relatively quick procedure was then used in an attempt to isolate mtDNA from the sponge tissue, but upon analysis by agarose gel electrophoresis no mtDNA was detectable.