Evaluation and Verification of a microRNA Panel Using Quadratic Discriminant Analysis for the Classification of Human...

Area of Science:

• Forensic science
• Molecular biology
• Genetics

Background:

• MicroRNA (miRNA) analysis is of significant interest for forensic body fluid identification.
• Co-extraction and detection of miRNAs in DNA extracts offer a streamlined alternative to other RNA-based methods.

Purpose of the Study:

• To evaluate the efficacy of miRNA expression profiling for body fluid identification directly from DNA extracts.
• To assess the reliability of a previously developed miRNA panel and model across diverse populations and compromised samples.

Main Methods:

• A panel of eleven miRNAs was used with a quadratic discriminant analysis (QDA) model.
• miRNA expression was analyzed from DNA extracts of various body fluids (blood, feces, urine, saliva, semen, vaginal secretions) from 50 donors each.
• The model's performance was tested on diverse population samples and compromised specimens.

Main Results:

• Initial classification accuracy of 87% from DNA extracts increased to 92% with the addition of three miRNAs.
• Reliable identification across mixed age, ethnicity, and sex populations was observed (72-98% accuracy).
• Classification accuracy varied for compromised samples and across biological cycles, with semen and saliva showing potential classification failures.

Conclusions:

• Body fluid classification is feasible using miRNA expression directly from DNA extracts, eliminating the need for separate RNA extraction.
• This approach significantly reduces evidentiary sample consumption and processing time for forensic laboratories.
• Further research is needed as compromised semen and saliva samples may not classify correctly, and mixed sample classification remains untested.