Laser Capture Microdissection and Isolation of High-Quality RNA from Frozen Endometrial Tissue

Laser capture microdissection (LCM) allows expression profiling of specific cell populations within tissues. However, isolation of high-quality RNA from laser capture microdissected frozen tissue is beset by problems arising from intrinsic tissue RNase activity. Herein, we describe an optimized staining/LCM/RNA extraction protocol developed for the isolation of epithelial RNA from frozen tissue sections using human endometrial cancer as a model tissue. This method combines excellent, reproducible visualization of tissue morphology with the isolation of high-integrity RNA suitable for downstream applications such as expression microarray analysis. We present quantitative and qualitative RNA data obtained from >200 endometrial epithelial samples (normal, hyperplastic, and cancerous), where 92% of samples had RIN values of 7 and above and highlight common pitfalls faced by investigators. This method should also be broadly applicable to a range of other tissue types.