Cell Line Macroarray: An Alternative High-Throughput Platform to Analyze hiPSC Lines.

In the past decade, tissue microarray (TMA) technology has evolved as an innovative tool for high-throughput proteomics analysis and mainly for biomarker validation. Similarly, enormous amount of data can be obtained from the cell line macroarray (CLMA) technology, which developed from the TMA using formalin-fixed, paraffin-embedded cell pellets. Here, we applied CLMA technology in stem cell research and in particular to identify bona fide neogenerated human induced pluripotent stem cell (hiPSC) clones suitable for down the line differentiation. All hiPSC protocols generate tens of clones, which need to be tested to determine genetically stable cell lines suitable for differentiation. Screening methods generally rely on fluorescence-activated cell sorting isolation and coverslip cell growth followed by immunofluorescence; these techniques could be cumbersome. Here, we show the application of CLMA to identify neogenerated pluripotent cell colonies and neuronal differentiated cell products. We also propose the use of the automated image analyzer, TissueQuest, as a reliable tool to quickly select the best clones, based upon the level of expression of multiple pluripotent biomarkers.

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.