DNA Degradation: The Effect of Oil Red O on Recovered DNA

Forensic examiners must decide which fingerprint enhancement technique is best fit for further downstream DNA processing. The dominant understanding is to limit the number of enhancement techniques on fingerprints since more DNA is lost the more enhancement techniques are applied. Literature studies perform these experiments with samples stored in room temperature or freezer conditions and have DNA tested from time points of hour 0, hour 24, 7 days, and 14 days. Although this is common literature practice, crime labs across the United States test their DNA evidence across a large range of days with the latest being an average of about 140 days after booking. This study investigated the effects of the single reagent Oil Red O (ORO) combined with DNA while being in-solution and dried on microscope slides in either room temperature or freezer conditions. Samples were collected at hourly time points of 0, 1, 2, 4, 8, and 24 hours along with day time points of 0, 1, 2, 7, 14, 28, 35, 56, 84, 112, and 140 days. DNA was extracted using the phenol-chloroform gold standard extraction method and quantified with Quantifilier™ Trio DNA Quantification kit. DNA quantities and the DNA degradation index were analyzed. Due to untreated samples and ORO-treated samples yielding insignificant results between DNA quantities, it is concluded that ORO does not affect the quantity of DNA found. However, since there was a statistically significant difference in DNA degradation, ORO, through some unknown mechanism, negatively affects the quality of DNA. The significant difference in DNA quantities through passing storage time is therefore concluded to be due to time itself and not ORO.