Reverse phase protein microarrays (RPPA) and laser capture microdissection (LCM) are "sibling" technologies that originated from the same laboratory to overcome the challenge of quantifying low-abundance proteins in heterogeneous tissues. Combining both technologies provides both unique opportunities and unique challenges. Enabling the unprecedented resolution of the activation state of labile biomarkers, such as phosphorylated cell signaling proteins, has had a substantial impact on our understanding of diseases and is playing a significant role in clinical trials. At the same time, quantifying proteins at this sensitivity in very small amounts of material requires cognizance of pre-analytical variability and the limits of downstream detection technologies. Here, we discuss both the potential that the combination of both technologies presents and the potential pitfalls that must be navigated.
Keywords: Diaminobenzidine; Fluorescence; Laser capture microdissection; Phosphoprotein; Pre-analytical variability.