Objective: To seek simple and cost-effective extraction technique to improve multiplex STR amplification from minimal oral epithelial cell samples.
Methods: One hundred DNA samples of oral epithelial cells extracted by mini system Chelex-100 method were quantitated by ABI 7500 Real Time System and were then typed with Identifiler system in ABI 3130 Genetic Analyzer.
Results: The DNA contents of different categories of samples were as followings: suck pipes (0.72-116.78 ng), cup edges (2.15-142.5 ng), mouths of drink bottle (1-34.65 ng), chopsticks (3.35-26.6 ng), fruit cores (0.294-21.4 ng), and poultry bones (0.88-5.88 ng). The mean successful typing rate for gender and more than 9 STR loci was about 59.38%. Except the addition or no addition of proteinase K to the samples, all other factors-C users' variation, sample extraction methods, and qualities and properties of the samples had considerable effects on the contents of extracted DNA.
Conclusion: Successful STR typing can be achieved in about 60% minimal oral epithelial cell DNA samples extracted by mini Chelex system.