Evaluation of cross-sample contamination in tissue microarrays by polymerase chain reaction.

In the past decade, the popularity and power of Tissue Microarray (TMA) technology has increased since it provides a method to detect diagnostic and prognostic markers in an array of clinical tissue specimens collected for translational research. TMAs allow for rapid and cost-effective analysis of hundreds of molecular markers at the nucleic acid and protein levels. This technology is particularly useful in the realization of the Human Protein Atlas Project, since it aims to create a reference database of non-redundant human proteins. In this context, it is important to assure the lack of cross-sample contamination due to the repeated use of the same needle in consecutive coring. Here we show that carry-over contamination from one tissue core to another does not occur, reinforcing the accuracy of the TMA technology in the simultaneous testing of multiple bio-samples.

Application of Tissue Microarray Technology to Stem Cell Research.

There is virtually an unlimited number of possible Tissue Microarray (TMA) applications in basic and clinical research and ultimately in diagnostics. However, to assess the functional importance of novel markers, researchers very often turn to cell line model systems. The appropriate choice of a cell line is often a difficult task, but the use of cell microarray (CMA) technology enables a quick screening of several markers in cells of different origins, mimicking a genomic-scale analysis. In order to improve the morphological evaluations of the CMA slides we harvested the cells by conventional trypsinization, mechanical scraping and cells grown on coverslips. We show that mechanical scraping is a good evaluation method since keeps the real morphology very similar to those grown on coverslips. Immunofluorescence images are of higher quality, facilitating the reading of the biomarker cellular and subcellular localization. Here, we describe CMA technology in stem cell research.