Concentration and Purity DNA Spectrophotometer: Sodium Monofluorophosphate forensic impended effect

Abstract

Background: A number of factors have been identified to affect DNA analysis for forensic purposes. SMFP compound which is constituted in toothpaste is one of those factors identified to cause this effect. The impact of this compound in forensic science is far evidenced to contaminate, inhibit and destroy biological samples. Toothbrush, one of preferable forensic evidences to recover biological sample in contact (brushing); might not be useful in identifying an individual if the person used toothpaste of SMFP compound. The SMFP reaction leads to inhibited band visualisation, concentration and purity contamination that lead to a failed analysis. This study presents experimental observational findings on the detrimental effects of the compound on DNA concentration and purity profiled from sample recovered from toothbrush. Results: Using spectrophotometer with complementary findings from electrophoresis, it was found that among the ten samples analysed one sample had extreme DNA concentration of 371 μg/ml with minimal purity measurement A260/A280 ratio of 1.25. Concentration analysed portrays the detrimental effect that damage and destroy DNA molecules into increased segmented molecules. Purity readings suggest the lowered amount of intact DNA molecules that would be enough to make into PCR. Also, PCR and electrophoresis method portrayed inhibition and failed visualisation of sex gene band contrast. Twofold phenomena emerged: limited DNA targeted locus for electrophoresis and DNA ionic irresponsive interactions. These are suggested by a twofold causation; one being non-polymerisation of the targeted DNA region and the other was destructed molecular structure acted by SMFP respectively. Conclusion: SMFP compound impedes concentration and purity of DNA physical samples, thereby affecting the physical sample by hindering forensic profiling through damaging DNA molecule to a no applicability and acceptability state. These findings verdict contributes to the understanding of SMFP constituted toothpaste action on biological sample during DNA forensic analysis.

The Use of Touch DNA Analysis in Forensic Identification Focusing on Short Tandem Repeat-Combined DNA Index System Loci THO1, CSF1PO and TPOX

“…The average DNA level of all samples was at a minimum amount of 0.25 ng with a purity of 1.8-2 (Table 1). [16][17][18] PCR products were visualised using Polyacrylamide Agarose Composite Gel Electrophoresis (PAGE) and the gel was stained with silver. To amplify the STR CODIS locus, the standard primers (THO1, TPOX and CSF1PO) were used and all buccal swab and property (watch and cellphone) swab samples showed positive results signifying a 100% detection.…”

Comparison of DNA Extraction and Amplification Techniques for Use with Engorged Hard-Bodied Ticks

“…Each method has been documented in the literature for use with unengorged ticks [9,10,28], though their use with engorged ticks has not been investigated thoroughly. When extracting DNA from engorged ticks, both the total concentration of DNA and the purity of that DNA are important for subsequent PCR amplification [29,30]. As mammalian proteins commonly found in the blood have been shown to be inhibitory to PCR, and engorged ticks are full of mammalian blood, the ability of an extraction method to effectively separate DNA from these mammalian proteins is imperative [12][13][14].…”

Molecular detection and antibiogram of Shiga toxin-producing Escherichia coli (STEC) from raw milk in and around Bahir Dar town dairy farms, Ethiopia

“…The purity and concentration of the extracted DNA were measured using a Nanodrop 2000/2000C Spectrophotometer (Thermo Scientific™, USA). A ratio of 1.6–2.0 margin is accepted as a pure DNA [ 29 ]. Then, the PCR test was employed in a final 25 μl reaction volume, of which 2.5 μl of PCR buffer with 7.5 mM MgCl2 (10X, HiMedia), 1 μl of dNTP (100 Mm, HiMedia), 0.5 μl of forward and reverses primers each (Bioneer), 0.5 μl of Taq DNA polymerase (5 U/μl, Solis BioDyne), 3 μl of template DNA and 17 μl of nuclease-free water.…”