Technical note: Efficient protocol for isolation of total ribonucleic acid from lyophilized fat and muscle pig samples.

Isolation of total RNA from frozen muscle and fat samples typically results in small yields due to the presence of connective tissue between muscle fibers, which impairs complete tissue homogenization, and the excess of fat and relatively small cellularity of adipose tissue. Meat quality studies involve determination of fatty acid composition and content from muscle and subcutaneous fat samples, a process that may produce an excess of lyophilized tissue samples. The purpose of this work was to investigate the stability of total RNA in lyophilized tissue samples generated during the routine detection of fatty acid content of pig muscle and fat tissues, stored at room temperature or at -20 degrees C. The protocol described here results in increased yields of total RNA from freeze-dried samples stored at -20 degrees C, which facilitates the homogenization step. The isolated RNA is suitable for common gene expression techniques such as final point and quantitative reverse transcription-PCR.