Quality and Quantity of DNA from Fresh and Long Term Stored Samples

Quality of genomic DNA is an important issue for the development of molecular markers because, in order for DNA to serve as a template for Polymerase Chain reaction (PCR), the entire sequence to be amplified must be present on a single DNA molecule. If the DNA is broken down into very small fragments, then the target sequence in the genomic DNA template is more likely to be disrupted by random breaks.

High quality genomic DNA has large average fragment size and low quality genomic DNA has small average fragment size due to breakage and enzymatic degradation of the DNA during purification or even during storage of the tissue sample. Both metabolic and environmental factors can cause DNA damage and fractionate/degrade DNA. In this study we have compared the quality and quantity of extracted DNA from fresh, old, and freeze dried plant samples to find out which are the most suitable samples for DNA extractions and downstream application such as PCR. Quality and quantity was determined using a Nanodrop 1000 Spectrophotometer (Thermo Scientific, Wilmington, DE) and by agarose gel electrophoresis. Results showed that DNA from fresh plant material was the best while old samples resulted in no/low quality and quantity DNA.