Real-time PCR detection of five different "endogenous control gene" transcripts in forensic autopsy material

Area of Science:

• Molecular Biology
• Forensic Science
• Gene Expression Analysis

Background:

• Quantitative real-time reverse transcription (RT)-PCR is standard for gene expression analysis.
• Accurate quantification relies on normalizing data against stable endogenous control genes.
• Postmortem samples often have extended postmortem intervals (>10 hours), potentially affecting control gene stability.

Purpose of the Study:

• To evaluate the stability of commonly used endogenous control genes in human tissues over extended postmortem intervals.
• To determine if specific control genes are more reliable for gene expression studies in autopsy samples.

Main Methods:

• RNA extraction from human skeletal muscle, heart, and brain tissues.
• Real-time RT-PCR to obtain Ct values for five control genes (beta-actin, B2M, CyPA, TBP, UBC).
• Analysis of Ct value stability across five postmortem intervals (15-118 hours).

Main Results:

• Skeletal muscle tissue showed relatively stable Ct values for control genes across postmortem intervals.
• Heart and brain tissues exhibited high variability in all tested endogenous control genes.
• B2M demonstrated the least instability among controls in this study, but overall variability was significant.

Conclusions:

• Commonly used endogenous control genes display considerable variability in postmortem human tissues.
• Postmortem mRNA degradation is complex, impacting the reliability of single control gene normalization.
• Erroneous data interpretation can result from using a single endogenous control; further research with more samples is recommended.