RESUMEN
With the advent of the genomic era, there is an increasing use of high-throughput techniques to generate transcriptome- and proteome-based profiles of biological specimens. Each of these methodologies offers a unique window into the inner workings of cell and tissue samples. Often, these studies generate large data sets and provide investigators with a substantial number of candidate dysregulated genes and pathways. Follow-up studies are then undertaken to independently validate the original findings and to extend the study to additional samples or more quantitative measurements. Although there are several methods available for these validation efforts, they are often tedious and laborious to perform; thus, additional tools that enable this task are needed. One such approach is layered expression scanning (LES), a new technique developed via a cooperative research and development agreement (CRADA) between the National Cancer Institute and 20/20 GeneSystems, Inc. The technique is based on the movement of biomolecules from a two-dimensional life science platform (histological tissue section, electrophoresis gel, multi-well plate, etc.) through a set of analysis membranes while maintaining the original distribution pattern of the molecules. Each membrane measures one analyte and the data are then mapped back to the original specimen, permitting each component of the life science platform to be studied in detail. LES can be configured in several different ways depending on the goals of the study. In this review, we summarize the use of the LES technique for a variety of biological applications.