Self-collection of oral epithelial cell DNA under instruction from epidemiologic interviewers

Oral epithelial cells provide an easily accessible source of germline DNA. Two methods for collection were compared in a 1992-1995 case-control study of oral cancer in Puerto Rico. One group of subjects (55 controls without o ral cancer) collected oral rinse samples at home or work under the directio n of a nonmedically trained interviewer ("self-collection"); the other grou p (94 controls) participated in a clinic-based collection, which also inclu ded blood and urine samples, conducted by a medical technician ("clinic col lection"). Participation was higher for self-collection (98.2%) than for cl inic collection (70.7%) (p < 0.001). DNA yields ranged from 2.0 to 204.5 mu g (median, 25.9 mu g) and did not differ by collection method, although yi elds varied by interviewer among self-collected samples (p = 0.02). Success rates for polymerase chain reaction amplification of the ADH3, NAT1, and m ultiplex CYP1A1/GSTT1/GSTM1 genotyping assays ranged from 76.4% (NAT1) to 9 8.2% (ADH3) for self-collected samples and were similar to those for clinic -collected samples (87.2-97.9%). Failure to amplify was associated with low DNA content (p = 0.015). Similar results were observed among cases (91 sel f-collected, 66 clinic collected), except that DNA yields did not vary by i nterviewer and a larger fraction (10.2%) of samples contained less than 5 m u g of DNA, perhaps because of disease-related oral impairment. Self-collec tion of oral epithelial DNA samples appears satisfactory and efficient for many epidemiologic studies.