Identification of organ tissue types and skin from forensic samples by microRNA expression analysis.

The identification of organ tissues in traces recovered from scenes and objects with regard to violent crimes involving serious injuries can be of considerable relevance in forensic investigations. Molecular genetic approaches are provably superior to histological and immunological assays in characterizing organ tissues, and micro-RNAs (miRNAs), due to their cell type specific expression patterns and stability against degradation, emerged as a promising molecular species for forensic analyses, with a range of tried and tested indicative markers. Thus, herein we present the first miRNA based approach for the forensic identification of organ tissues.

Differentiation of five body fluids from forensic samples by expression analysis of four microRNAs using quantitative PCR.

Applying molecular genetic approaches for the identification of forensically relevant body fluids, which often yield crucial information for the reconstruction of a potential crime, is a current topic of forensic research. Due to their body fluid specific expression patterns and stability against degradation, microRNAs (miRNA) emerged as a promising molecular species, with a range of candidate markers published. The analysis of miRNA via quantitative Real-Time PCR, however, should be based on a relevant strategy of normalization of non-biological variances to deliver reliable and biologically meaningful results.

Assessment of STR Typing Success Rate in Soft Tissues from Putrefied Bodies Based on a Quantitative Grading System for Putrefaction.

To date, there is no systematic investigation of the association of short tandem repeat (STR) typing success rate in soft tissues with different signs of putrefaction. Herein, putrefaction was rated using a newly developed 19-parameter system in soft tissues from a collective of 68 decaying bodies, and DNA yield was determined in 408 samples. DNA integrity was rated using a self-devised pentaplex PCR generating an "integrity score" (Si).

An evidence based strategy for normalization of quantitative PCR data from miRNA expression analysis in forensic organ tissue identification.

Messenger-RNA (mRNA)-based analysis of organ tissues and their differentiation in complex crime stains has recently been introduced as a potential and powerful tool to forensic genetics. Given the notoriously low quality of many forensic samples it seems advisable, though, to substitute mRNA with micro-RNA (miRNA) which is much less susceptible to degradation. However, reliable miRNA detection and quantification using quantitative PCR requires a solid and forensically relevant normalization strategy.

An evidence based strategy for normalization of quantitative PCR data from miRNA expression analysis in forensically relevant body fluids.

Micro-RNA (miRNA) based analysis of body fluids and composition of complex crime stains has recently been introduced as a potential and powerful tool to forensic genetics. Analysis of miRNA has several advantages over mRNA but reliable miRNA detection and quantification using quantitative PCR requires a solid and forensically relevant normalization strategy. In our study we evaluated a panel of 13 carefully selected reference genes for their suitability as endogenous controls in miRNA qPCR normalization in forensically relevant settings.