Fingerprint Enhancement Revisited and the Effects of Blood Enhancement Chemicals on Subsequent Profiler Plus™ Fluorescent Short Tandem Repeat DNA Analysis of Fresh and Aged Bloody Fingerprints

Abstract

This study was aimed at determining the effect of seven blood enhancement reagents on the subsequent Profiler Plus™ fluorescent STR DNA analysis of fresh or aged bloody fingerprints deposited on various porous and nonporous surfaces. Amido Black, Crowle's Double Stain, 1,8-diazafluoren-9-one (DFO), Hungarian Red, leucomalachite green, luminol and ninhydrin were tested on linoleum, glass, metal, wood (pine, painted white), clothing (85% polyester/15% cotton, 65% polyester/35% cotton, and blue denim) and paper (Scott ® 2-ply and Xerox-grade). Preliminary experiments were designed to determine the optimal blood dilutions to use to ensure a DNA typing result following chemical enhancement. A 1:200 blood dilution deposited on linoleum and enhanced with Crowle's Double Stain generated enough DNA for one to two rounds of Profiler Plus™ PCR amplification. A comparative study of the DNA yields before and after treatment indicated that the quantity of DNA recovered from bloody fingerprints following enhancement was reduced by a factor of 2 to 12. Such a reduction in the DNA yields could potentially compromise DNA typing analysis in the case of small stains. The blood enhancement chemicals selected were also evaluated for their capability to reveal bloodmarks on the various porous and nonporous surfaces chosen in this study. Luminol, Amido Black and Crowle's Double Stain showed the highest sensitivity of all seven chemicals tested and revealed highly diluted (1:200) bloody fingerprints. Both luminol and Amido Black produced excellent results on both porous and nonporous surfaces, but Crowle's Double Stain failed to produce any results on porous substrates. Hungarian Red, DFO, leucomalachite green and ninhydrin showed lower sensitivities. Enhancement of bloodmarks using any of the chemicals selected, and short-term exposure to these same chemicals (i.e., less than 54 days), had no adverse effects on the PCR amplification of the nine STR systems surveyed (D3S1358, HumvWA, HumFGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820) or of the gender determination marker Amelogenin. The intensity of the fluorescent signals was very similar and the allele size measurements remained constant and identical to those of untreated bloody fingerprints. No additional background fluorescence was noted. Continuous exposure (for 54 days) to two of the seven enhancement chemicals se-354

Application of forensic luminol for blood detection in endodontic files

“…The amount of blood detected varied according to the case in which the endodontic file was collected, agreeing with the findings of Frégeau et al 24 who reported that luminol could be used to detect the presence of very small quantities of blood or blood stains diluted up to a 1:10 6 ratio.…”

Assessing the impact of common forensic presumptive tests on the ability to obtain results using a novel rapid DNA platform

“…There is some evidence to suggest that inhibition has a greater impact on extremely low template samples [20] or is observed as a function of time between presumptive testing and STR profiling [21,22]. Given these observations, the data presented supports the use of ParaDNA technology on high template and medium template samples, which in the context of the present study would include the blood, saliva and semen stains.…”

Biological traces at the crime scene

“…Tragove nastale prijenosom krvi dodirom na drugi predmet nazivamo otisci ili brisotine 16,17 . Na taj se način mogu prenijeti otisci prstiju, dlana, stopala, gume vozila te mogu imati individualne značajke, što može pomoći u identifikaciji počinitelja kaznenog djela 18 . Brisanjem ili slučajnim povlače-njem dijela tijela ili predmeta po drugom dijelu tijela ili predmeta nastaju brisotine 19,20 .…”