Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.


Sci. STKE, 4 February 2003
Vol. 2003, Issue 168, p. pl2
[DOI: 10.1126/stke.2003.168.pl2]


Alkaline Phosphatase Fusion Proteins as Affinity Probes for Protein Localization Studies

Caroline Brennan* and Jez Fabes

School of Biological Sciences, Queen Mary, University of London, LONDON E1 4NS UK

Abstract: The receptor affinity probe or receptor alkaline phosphatase (RAP) staining method uses soluble protein ectodomains fused to secreted placental alkaline phosphatase to locate ectodomain binding sites within cells or tissues. We have used this approach to identify expressing cells in tissue culture, in tissue sections, or in whole-mount embryos. The RAP method is especially useful in situations where a reliable monoclonal antibody is not available or if an orphan receptor is the focus of the study. The technique permits localization of both receptors and ligands and is readily quantifiable for cell-surface binding assays. Soluble ectodomain placental alkaline phosphatase fusion proteins are therefore highly sensitive reagents that permit the direct localization of available binding sites through simple chromogenic assays without purification, radioactive labeling, or secondary reagents.

*Corresponding author. E-mail: c.h.brennan{at}

Citation: C. Brennan, J. Fabes, Alkaline Phosphatase Fusion Proteins as Affinity Probes for Protein Localization Studies. Sci. STKE 2003, pl2 (2003).

Read the Full Text

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882