A Reverse Phase Array (RPA) is a type of protein array where lysates generated from cell lines, tissue samples, blood samples, or any other source of proteomic material are arrayed in a micro dot-blot format.  The technique, originally introduced by Dr. Lance Liotta and Dr. Emanuel Petricoin, provides a new platform for measuring protein expression levels in a large number of biological samples simultaneously.  

One common detection methodology for RPAs involves colorimetric detection via amplification step involving tagged secondary antibodies. The RPA data, viewed as series of dilution curves, provides a sensitive, quantitative, and much higher throughput alternative to Western blotting.

Image 1. Reverse Phase Array (Low Density Lysate and Serum Array)

Low density arrays (Image 1) employing fairly large features are useful for clinical sample profiling where the sample number is small, while high density arrays (Image 2) are essential for large-scale pathway analysis.

Image 2. Reverse Phase Array (High Density Lysate and Serum Array)

Aushon BioSystems’ 2470 arrayer is a proven technology for building exceptionally high quality Reverse Phase Protein Lysate microarrays. The 2470 can produce arrays of the often viscous lysate material with the linearity and consistency to permit data extraction from dilution series curves.