Total RNA-Based Target Design for Microarray Analysis of Defined Tumor Areas

Efficient gene expression analysis at the cellular level using microarrays requires the development and successful implementation of a variety of laboratory strategies. Major problems that have to be overcome are to efficiently obtain high-purity and quality RNA from limited amounts of neoplastic cells separated from contaminating normal cells and to perform linear and reproducible RNA amplification. Previous studies demonstrated that 50 000–200 000 cells (7) or 50 ng to 1 μg total RNA (5) are feasible for generating target samples for hybridization of microarrays for gene expression profiling. We developed a concise guide to a total RNA-based target design for mi-