Determinants Of Dna Yield And Quality From Different Non-Invasive Sampling Methods

ABSTRACT

Aim: The purpose of this study was to determine theDNA yield and quality from different non-invasivesampling methods and to identify the method whichgave the highest DNA yield. Method: Thirty-eightvolunteers had been recruited in this study whereblood, buccal cells and saliva were collected usingvarious collection techniques. Buccal cells werecollected by 1) cytobrush and 2) saline mouth rinsingor “swish”. Meanwhile saliva was collected by passivedrooling method. Upon processing the white bloodcell (WBC), buccal cells and saliva samples, DNAextraction was performed according to themanufacturer’s protocol. Quantification and quality(DNA ratio at A260/A280) of the extracted DNA weredetermined using NanoDropND-1000®. T-test wasperformed to compare means between DNA obtainedfrom various collection methods. Results: DNA yieldsfrom buccal cells collected with cytobrush, “swish”,saliva and WBC (mean ± SD) were (8.2 ± 5.9)ng/μl,(28.2 ± 14.9)ng/μl, (5.9 ± 9.5)ng/μl and (105.3 ±75.0)ng/μl respectively. Meanwhile the mean DNAratio at A260/A280 for cytobrush, “swish”, saliva andWBC were 2.3, 2.0, 1.7 and 1.8 respectively. Post hoctest with Bonferroni correction suggested that DNAyield from “swish” technique exhibited the least meandifferent as compared to the DNA extracted from WBC(p<0.05). There was no significant difference in themean quality of the DNA extracted from WBC, salivaand buccal cells collected in these non-invasivemethods (p=0.323). Conclusion: The “swish”technique of obtaining buccal cells yielded thehighest amount of DNA and was of the quality of DNAextracted from blood sample.Key words buccal cells; non-invasive methods;cytobrush; “swish”; saliva; DNA yield; DNA quality