Identification, forensic evidences and effect of the most used lip cosmetics on the human STR profiling at Kingdom of Saudi Arabia

Abstract

This study aimed to identify the DNA STR profiles that were obtained from the lips with various lip cosmetics involved in lip pencil, lipsticks and lip gloss for a brand – Makeup Forever and lip balms (Labello brand) – have been popularly used by Saudi women at KSA. The study was involved 35 unrelated participants (healthy female donors) aged between 26 and 32. The swabbing of lip cosmetics was done prior to using them as negative control samples, other sterilized swabs were collected from the used lip cosmetics which contained the lip cells for each participant as a study sample. Moreover, the buccal swabs were firmly collected from the cleaned oral cavities for the same donors as reference samples. The air-drying of the collected swabs was done for ten minutes at room temperature and then stored them at − 20 °C before the DNA analysis. The 7500 Real-Time PCR (qRT-PCR) was quantified the extracted DNA. The amplification of 16 STR loci was done using the AmpFlSTR® Identifiler® PCR amplification kit using the Thermocycler ABI 9700 to amplify the extracted DNA. The Applied Bio-systems 3130™ Genetic Analyzer with Gene Mapper® ID-X Software v3.5 was used to analyze the PCR products. The data for quantifying DNA recorded significant decrease in the concentrations of DNA samples ranged from 0.15 to 0.55 ng/µL in comparison to the reference samples, while DNA was not detected in all the negative control samples. Some STR loci showed considerably high inhibition and low heterozygosity loss in the study samples compared to the reference and negative samples. The possibility of extracting DNA samples from lip cosmetics were used in the present study could be useful and successful in some cases due to the effect of the chemical compositions such as heavy pigments, organic components, and aromatic wax on the STR profiles in the lip cosmetics, especially in the lipsticks, lip glosses and lip pencils.