April 2, 2002

James L. Wittliff, Ph.D., M.D.

Cellular heterogeneity of tissue specimens has been a complicating factor in assessing analyte levels in specific cell types. Laser capture microdissection (LCM) represents a breakthrough technology for collecting homogeneous populations of intact cells from solid tissue sections and ascites samples for molecular analyses. Cells can be collected based on either morphologic or immunohistologic features. Molecular techniques that have been applied to samples of cells selected by LCM include RT-PCR amplification, loss of heterozygosity (LOH), microsatellite instability, differential gene profiling, and cDNA microarrays for genomics as well as, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) analyses of protein products, Western blotting, immuno-quantification and MAMDI-TOF mass spectrometry for proteomics. LCM allows direct comparisons of gene amplification and expression with protein appearance in normal and diseased cells of the same tissue specimen. Combinations of these analytic procedures with LCM will advance molecular diagnosis, assessment of prognosis, therapy selection and monitoring therapy response.