# Freezing tissues pre-homogenisation reduces degradation and yields improved quality RNA in the mouse lung

## TL;DR

Freezing mouse lung tissues before processing preserves RNA quality better than not freezing them.

## Contribution

A simple and affordable quick-freezing method improves RNA integrity during extraction from tissue samples.

## Key findings

- Frozen tissues produced higher-quality RNA with less degradation compared to non-frozen tissues.
- Agarose gel electrophoresis showed more intact RNA in frozen samples.
- The freezing step is a practical way to enhance RNA extraction quality.

## Abstract

Ribonucleic acid (RNA) extraction requires meticulous sample handling to ensure purity and integrity. Although a variety of commercial kits are available, along with optimised protocols, pre-extraction sample processing remains a challenging procedure, especially with tissue samples. In our brief report, we describe the beneficial impact of freezing tissues before homogenisation on the quality of RNA extraction. Lung tissues were freshly excised from mice and homogenised with or without prior quick freezing in a freezer. Then, RNA was extracted according to the protocol provided with a commercial column-based RNA extraction kit. RNA quality was analysed by UV absorbance and agarose gel electrophoresis. We found that the frozen tissues yielded better-quality, more intact RNA than the non-frozen tissues, possibly due to lower temperatures during homogenisation. “Smearing”, indicative of RNA degradation, was visible in some of the non-frozen samples. The extra quick-freezing step provides a simple and affordable method for preserving high-quality RNA, especially from tissue samples. Further comparisons can be made to determine whether the observed benefits extend to other tissue types or to quantitative polymerase chain reaction (qPCR) analysis in gene expression studies.

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From: Freezing tissues pre-homogenisation reduces degradation and yields improved quality RNA.•Pre-extraction of tissue samples requires a meticulous sample handling procedure•Freezing tissues prior to homogenisation yields better quality and purity of RNA•More intact RNA is observed in frozen tissues using gel electrophoresis•The quick-freezing method benefits RNA extraction using an affordable and less time-consuming procedure

Pre-extraction of tissue samples requires a meticulous sample handling procedure

Freezing tissues prior to homogenisation yields better quality and purity of RNA

More intact RNA is observed in frozen tissues using gel electrophoresis

The quick-freezing method benefits RNA extraction using an affordable and less time-consuming procedure