Forensic applications of laser capture microdissection: use in DNA-based parentage testing and platform validation

Area of Science:

• Forensic Science
• Molecular Biology
• Genetics

Background:

• Maternal tissue contamination can complicate DNA analysis from products of conception.
• Accurate isolation of fetal DNA is crucial for forensic applications like parentage testing.

Purpose of the Study:

• To evaluate Laser Capture Microdissection (LCM) for isolating human chorionic villi from admixed maternal tissue.
• To assess the utility of LCM-derived DNA for forensic short tandem repeat (STR) analysis in parentage testing.
• To validate the LCM platform using archival formalin-fixed fetal tissues.

Main Methods:

• Laser Capture Microdissection (LCM) was employed to selectively isolate fetal chorionic villi from maternal decidua in paraffin-embedded tissue sections.
• DNA was extracted from the isolated villi and amplified using polymerase chain reaction (PCR) for 9-15 STR loci.
• The LCM procedure was validated on archival products of conception (POC) tissues.

Main Results:

• Sufficient quantity and quality of DNA were obtained from LCM-isolated fetal cells for successful forensic parentage testing.
• Polymerase chain reaction (PCR) amplification of short tandem repeat (STR) loci was feasible with the extracted DNA.
• Validation studies demonstrated reproducibility of the LCM protocols and procedures for tissue separation.

Conclusions:

• Laser Capture Microdissection (LCM) is a reliable tool for forensic applications requiring high specificity of cell populations.
• LCM enables accurate isolation of fetal DNA, crucial for parentage testing in cases involving mixed tissues.
• Caution is advised during pathology procedures to prevent extraneous DNA contamination.