Method for improved integrity of RNA isolated from Matrigel cultures

Matrigel is a commercially available substrate that is derived from the extracellular matrix. Matrigel is widely used in cell culture experiments such as the transdifferentiation of primary pancreatic acini to ductal epithelial-like cells. Difficulty arises during gene expression analysis for cells cultured on Matrigel because residual RNA in the Matrigel will not only contribute to the poor integrity of RNA isolated from Matrigel cultures, but also will impact the gene expression data. We report here a simple method of removing Matrigel from primary cultures of human or mouse pancreatic acini. Following the experiment, the cultures are placed on wet ice to liquefy the Matrigel. The cell and Matrigel mixture is then centrifuged at low speed to separate the pancreatic cells from the Matrigel solution that resides in the supernatant. RNA isolated from the pelleted cells has high integrity and may be readily used for gene expression analysis such as quantitative reverse transcription PCR.