Challenging and Rare DNA Profiling of Burned Corpses at the State Forensic Science Laboratory of Jharkhand

Research Article

Austin J Forensic Sci Criminol. 2017; 4(1): 1056.

Challenging and Rare DNA Profiling of Burned Corpses at the State Forensic Science Laboratory of Jharkhand

Nand JK*, Soren AN and Singh R

Division of DNA Biology Section, State Forensic Science Laboratory Jharkhand, India

*Corresponding author: Jwala Kumar Nand, State Forensic Science Laboratory, Ministry of Home Affairs, Near Birsa Munda Jail, Hotwar, Ranchi, Jharkhand - 835217, India

Received: January 03, 2017; Accepted: February 20, 2017; Published: February 21, 2017

Abstract

Burning of corpses, most common in, the criminals and heinous crime cases and for the destruction of evidence more corpses are burnt in cremation often for destruction of evidence to obscure the crime scene and buried in boxed or dumped in the river or the graveyard. It’s very cost effective reason to hide crime In the process of cremation temperatures about to 870-980°C (1,600-1,800°F) for 60-80 min or longer, after burning the dead body only leaving severely burnt teeth and some remains of long charred bones. In various criminal and civil cases, there is a requirement of DNA profiling for ascertained identity of the person and also help to solve the paternity-related issues. In the present study, we present autosomal DNA profiling of 12 corpses as the sample (legally known as exhibits) from the crime scene, one of the very sensational cases of state Jharkhand of India. The DNA profiling test performs in state forensic science laboratory Jharkhand. DNA extraction from charred bones, the human nuclear DNA was tested by highly sensitive multiplex PCR and quantified via real-time PCR; gene typing was done using the AmpFISTR Identifier Plus® kit.

Keywords: Cremation; Charred bones; AmpFISTR identifier plus®; Nuclear DNA

Introduction

Typing of short tandem repeats (STR, ‘‘DNA profiling”) is advanced tools When analyzing DNA extracted from human bones or teeth (modern or ancient), traces very minute amounts of DNA less than 1ng or highly degraded charged spongy tissues can use for identification purposes [1-3]. In forensic science laboratory DNA profiling is routine work, usually to confirm identity or post-obituary paternity testing. In cases of burial, the body can easily exhume for examination and scientific investigation. Due to the development of genetic analysis, e.g. Sequencing of nuclear short tandem repeats, biological material (i.e. Biopsies, blood samples, bones, hairs, teeth, saliva etc) taken for medicolegal examination can successfully be analyzed even after long time storage or properly preserved, while STR typing after cremation is of questionable value. Commercially available and globally accepted multiplex PCR AmpFISTR Identifiler Plus® kit which amplify up to 15 loci plus one gender locus Amelogenin gene in one reaction mixture and for highly degraded sample AmpFISTR Minifiler® kit which amplify up to 9 loci plus one gender locus Amelogenin [4-5].

PCR inhibitors

There are many PCR inhibitors that target the DNA polymerase directly or indirectly. Proteases or detergents present in the reaction can degrade this enzyme. For example, urea and phenol are known to degrade DNA polymerases. Calcium, collagen, hematin and tannic acid may inhibit polymerase activity, melanin forms a reversible complex with the DNA polymerase. Humic acids interact with the template DNA and the polymerase thus preventing the enzymatic reaction, even at low concentrations. High concentrations of calcium may lead to a competitive binding by the DNA polymerase instead of magnesium and complexing agents, magnesium is no longer available as a cofactor for the polymerase and its activity is decreased [6]. The samples resulting with complete inhibition treated with new dual cycle EtO-treated Microcon® DNA Fast Flow PCR-grade devices catalog No. MRCFOR100ET use for efficient concentration, desalting, or buffer exchange of aqueous biological samples. Our aim of this work was to systematically investigate whether human remains after cremation can be reliable for the establishment of individuality.

Case history

At the police station an FIR launch by police personhood under sections: 302/201/120(B)/34 of Indian Penal Code on the basis of secret information that a female, namely ABC Kumari (identity has been concealed), age 16 years killed brutally by their own family members and for destruction evidence they burned their dead body completely, after that all family members abscond. The investigation agency collected 17 blackish gray small charred bone pieces along with some ashes. It was received at state forensic science laboratory Jharkhand. From that so-called identity of person ascertain.

Materials and Methods

Sample

After cremation, the remains were collected by authority, 17 exhibits generally blackish gray small bones and some gray long bone as they were burned and charred it need screening and preprocessing.

Sample preparation

The surface of the skeletal element was removed using a sand paper in order to eliminate potential contamination and burnt tissue adhered to it, Samples were then cut into thin slices and washed twice with 5% sodium hypochlorite for 15 min, then rinsed properly and soaked in water for 15 min, once rinsed in 70% ethanol and finally rinsed in 100% ethanol. The samples were left to dry overnight at room temperature.

DNA extraction

From each, the respective bone piece makes a powder using liquid nitrogen one gram of bone powder was incubated in 10 ml of 0.5 M EDTA, pH 8.5 solution for 24 h at room temperature continuous rotation of the rotor at speed 40 RPM. The next day the list centrifuge at 3000 RPM for supernatant was discarded, and the EDTA solution was changed two more times. After 3- 4 days of decalcification each bone paste. We’re submerged in 400 μl of extraction buffer (10 mm Tris-Cl, pH 8.0, 0.1M EDTA, pH 8.0, 20 μg/ml RNase A, 0.5% SDS) in separate 15 ml capacity falcon tubes for 1 hours at 37 °C. Proteinase K (Mark GeNitm) (4mg/μl) was then added and incubated for further 12-15 hours at 56 °C with periodic swirling 120 RPM. The solution was brought to room temperature and subjected to Organic methods of DNA extraction. The tubes were stored at 4 °C until its use.

DNA quantification

DNA quantification of the 12 samples (Table 1) was performed by real-time polymerase chain reaction (RT-PCR) using the Quantifiler® Human DNA Quantification kit (Life Technologies Inc.) [7] Containing DNA standard solution (200ng/μl), Quantifier Human Primer mix, and Quantifier PCR Reaction Mix. Human Primer Mix (10.5 μl/sample) and PCR Reaction Mix (12.5 μl/sample) were mixed and then dispensed into reaction wells (23 μl each) followed by the addition of 2 μl of sample or standard DNA of known concentration to each well, to obtain a 25 μl PCR reaction system. The amount of DNA was calculated by the real-time PCR machine (Applied Biosystems) and Software: 7500 SDS V.1.2.3.

Identifier plus® PCR and electrophoresis

AmpFISTR Identifiler Plus® kit [8] was used to multiplex PCR reaction for co-amplification of 15 autosomal STRs loci and a gender locus (Table 2). Using 25 μl PCR amplification mixture (10.5 μl of PCR reaction mix, 5.5 μl of Identifier Plus® Primer Set, 9.0 μl of nucleasefree water and 1 μl of DNA template), amplification was carried out under conditions of initial denaturation at 95°C for 10 min, followed by 29 cycles of denaturation at 94°C for 1 min, annealing at 59°C for 1 min and extension at 72°C for 1 min, and a final extension step at 60 °C for 60 min. The PCR products were then examined using a 10-μl electrophoresis system containing 0.3 μl of Gene Scan™ 500 LIZ® Size Standard dye, 8.7 μl of Hi-Di™ formamide and 1.0 μl of PCR product or the AmpFlSTR® Identifiler Plus® allelic ladder. Capillary electrophoresis was performed on an ABI-3130 Genetic Analyzer using 36 cm 4-capillary array (Applied Biosystems). Sizing of the DNA fragments was carried out using Gene Mapper ID software v3.2 with respect to Gene Scan™ 500 LIZ® Size Standard. The resultant allelic distribution (genotypes) obtained from the studied loci in the exhibits is shown in the Table 2.

Citation: Langley NR and Jian W. Skeletal Age-at-Death Estimation from the Pubic Symphysis: A Test of Three Methods in a Chinese Population. Austin J Forensic Sci Criminol. 2016; 3(2): 1054. ISSN:2380-0801