Identification through DNA analysis is an accurate diagnostic tool. The DNA analysis is through Variable Number of Tandem Repeat (VNTR) and Restriction Fragment Length Polymorphisms (RFLP). VNTR is an examination based on the repetition of a particular base sequence. The duplication area of DNA with a base size of less than 1 kb is called the ‘microsatellite’ Short Tandem Repeat (STR).
Identification is a way of identifying individuals with characteristics and characteristics to distinguish them from others. Currently, the identification method has evolved towards molecular forensic DNA (Deoxyribonucleotic acid). DNA is the smallest unit in all living things ranging from microorganisms to higher organisms such as humans, animals, and plants.
At the crime scene, the skin surface of the offender’s body accidentally touched the surrounding objects. For example, sunglasses, watches, cellphones and so forth. So that the transfer of trace evidence occurs to the purpose. In this case, one of the technologies is touch DNA / contact trace DNA.
Until now, Indonesia has carried out personal identification through DNA touch examination (contact trace DNA) including glasses by taking wet sacra with 70% alcohol solution and distilled water. This research is expected to provide answers to matters related to the effective use of objects (trace evidence) as material forensic identification.
The DNA analysis is through STR CODIS loci: CSF1PO, THO1, and TPOX, which according to research (Evi Untoro, Atmadja, Pu, & Wu, 2009) shows that these three loci have the highest discriminatory power which is above 60-70% for the population in Indonesia
Method and Results
In the examination of DNA analysis, DNA levels are an essential factor in the success of amplification of DNA samples. If there is a decrease in DNA levels up to 1 ng, it has the potential to decrease the STR detection ability to 95%. DNA integrity is a significant concern for DNA forensic examination. This implies that even though the analysis of DNA levels obtained is relatively high, if DNA has undergone fragmentation or degradation, then high DNA levels become less meaningful.
The results of this study indicate the use of 70% alcohol solution collected more samples from the swab compared to using a distilled water solution.
6% of polyacrylamide has a high sensitivity value and caused by the presence of polygonal fiber patterns. Thus, DNA molecules that are small or degraded can still visualize the band.
Author: Dr. dr. Ahmad Yudianto, SpFM [K]., SH., M.Kes
Detail information from this research can be seen in our writing at:
Simon Martin Manyanza Nzilibili , Muh.Abduh Dwi Putra, Ahmad Yudianto, , Acrylamide versus Agarose Efficiency to recover trace DNA [without PCR] on 70% ethylated swab versus distilled water swab from spectacles. Journal Punjab Academic of Forensic Medicine Toxicology, Vol 19 No.1/ISSN 0972-5687, pp 136-141