Abstract
Background:Genomic DNA extraction for genotyping of rat is a common procedure in animal facilities. A suitable method of obtaining this DNA must not cause undue distress to the animal. Tail tip appears to be the most common sampling method for DNA extraction, both in young and adult rats. The aim of this study was to compare the quantity and quality of DNA extracted from tail tip and blood samples obtained from rats.Methods:Samples were collected from the tail and blood from seven rats aged 3.5 months and weighting 150-200 gram. DNA was isolated using commercial kits and concentrations and purity were determined by NanoDropLite spectrophotometry. The integrity of DNA was evaluated by agarose-gel electrophoresis.Results:DNA in all samples was extracted successfully but the intensities of bands after electrophoresis were heterogeneous. In general, DNA obtained from tail tip was more than that obtained from blood, with differences being not statistically significant (55.5± 26.40 ng/μL for tail tips; 46.6± 21.74ng/μL for blood; P= 0.2). The DNA purity (OD260/OD280) of DNA obtained from blood samples was slightly better than that obtained from tail tips, with differences being not statistically significant (1.87±0.09 for blood; 1.81±0.05 for tail tip; P= 0.1).Conclusions:Adequate amount and high-quality of DNA were obtained from blood and tail tissue of rats. These results support the previous recommendations for collection of minimal lengths of tail tissue from rats, making this method more suitable for the extraction of DNA from rat.