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Molecular identification of blood stains on different surfaces and fabrics using specific multiplex mRNA

Thesis

Last updated: 06 Feb 2023

Subjects

-

Tags

Forensic Medicine & Clinical Toxicology

Advisors

El-Barrani, Usama M. , Hanoun, Amani F. , Abdel-Fattah, Dina S. , Shehab, Alaa M.

Authors

El-Zahed, Hanaa Muhammad Muhammad

Accessioned

2017-07-12 06:41:06

Available

2017-07-12 06:41:06

type

M.D. Thesis

Abstract

In current forensic practice, blood stain identification is determined using enzymatic, immunologic and chemical testing. Recently, mRNA-profiling has emerged as an alternative strategy to identify the blood stains. mRNA profile clearly reveals tissue-specific gene expression patterns. HBB and HBA (the alpha and beta subunits of hemoglobin A) are specific mRNA blood biomarkers. This study aimed at identification of blood stains on different tested surfaces and fabrics for forensic application by molecular assessment of specific mRNA blood biomarkers. For this study, 100 blood samples were collected from healthy volunteers and they were classified into: (1) 9 groups, each group included 10 samples that were applied on 9 different fabrics and surfaces; cotton, wool, silk, synthetic nylon, wood, glass, ceramic, iron as a metal and leather. (2) One blood group included 10 samples that were applied on glass and exposed to humidity and high temperature to test their effect on mRNA. Ten saliva samples were collected from healthy volunteers and were applied on glass as a negative control body fluid. All samples were left to dry for 1 day. The next steps of the study were RNA extraction from blood and saliva dried stains, reverse transcription, performing gene expression analysis of the blood specific markers using RT-PCR then detection of the amplified gene using agarose gel electrophoresis. The results demonstrated that HBB and HBA can be recovered from blood stains in sufficient quantity and quality for mRNA analysis. There were mild interpersonal variations in HBB and HBA gene expression values. In addition, there were mild effects of various surfaces on HBB and HBA mRNA quantification. Temperature and humidity caused marked decrease in the level of mRNA. This study concluded that HBB and HBA are highly reliable, sensitive and specific genetic markers for blood stains identification. RT-PCR is valuable in blood identification by gene expression analysis of HBB and HBA. Temperature and humidity are important deleterious factors affecting mRNA integrity.

Issued

1 Jan 2014

DOI

http://dx.doi.org/10.21473/iknito-space/36228

Details

Type

Thesis

Created At

28 Jan 2023