Straightforward and sensitive RT-qPCR based gene expression analysis of FFPE samples

Area of Science:

• Molecular Biology
• Genomics
• Biotechnology

Background:

• Fragmented RNA from formalin-fixed paraffin-embedded (FFPE) tissues poses a significant challenge for accurate gene expression analysis.
• Existing methods often struggle with the low RNA integrity inherent in FFPE samples.

Purpose of the Study:

• To quantify the impact of RNA integrity, gene-specific reverse transcription, and targeted cDNA preamplification on reverse transcription polymerase chain reaction (RT-qPCR) sensitivity.
• To evaluate the effectiveness of these methods for gene expression analysis using FFPE material.

Main Methods:

• RT-qPCR was performed on FFPE samples (n=28) measuring 48 protein-coding genes.
• Investigated the effects of RNA integrity, gene-specific priming during reverse transcription, and targeted cDNA preamplification on assay sensitivity.

Main Results:

• Improved RNA integrity offered a modest 1.6-fold increase in gene detection sensitivity.
• Gene-specific priming during reverse transcription enhanced sensitivity by 4.0-fold.
• Targeted cDNA preamplification yielded the most substantial improvement, increasing sensitivity by an average of 172.4-fold.

Conclusions:

• Gene-specific reverse transcription and targeted cDNA preamplification are effective strategies for sensitive and accurate RT-qPCR gene expression analysis of FFPE samples.
• These methods are cost-effective and easily integrated into standard laboratory workflows, overcoming limitations of fragmented RNA.