DNA Extraction and Quantification Discussion

The average 260/280 ratio for RNase treated samples was 1.60, while the accepted ratio for pure DNA is approximately 1.8.  This is slightly low to be convinced that our RNase treated sample is pure DNA.  The 260/230 ratio average of 0.60 for RNase treated samples further justifies the impurity of the samples, because a pure nucleic acid should have a 260/230 ratio that is higher than the 260/280 ratio [6].  On the gel, the consistent presence of bands slightly above 10,000 b.p. indicates the presence of nondegraded genomic DNA in the samples.  In the RNase untreated samples, the fields of discoloration at less than 500 b.p. indicate the presence of RNA.  The RNase treated samples did not show these fields, indicating that the RNase worked to degrade the RNA to small enough lengths such that it was unnoticeable on the gel.  Although the RNA did not appear on the RNase treated gel, small RNA fragments were still in the solution even after RNase treatment.  This fact likely explains the NanoDrop results indicating impurities; because RNA was cut into smaller fragments by RNase does not entirely mean it cannot absorb.