EGFR SOMAmer specificity test.

<p>EGFR SOMAmer reagent was incubated with one of the ErbB proteins followed by labeling of bound protein with Alexa fluor 647. After extensive washing, photocleavage dissociates SOMAmer:protein complex from the bound beads, and the complex is separated by polyacrylamide gel electrophoresis under denaturing conditions. Lane 1, pulled down EGFR; Lane 2, EGFR standard; lane 3, pulled down ErbB2; lane 4, ErbB2 standard; lane 5, pulled down ErbB3; lane 6, ErbB3 standard; lane 7, pulled down ErbB4; lane 8, ErbB4 standard, and lane 9, MW size standards The EGFR SOMAmer showed limited cross-reactivity with ErbB family proteins. Relative to EGFR, the SOMAmer “pulled down” limited amounts of ErbB2 (0.4%), ErbB3 (6.9%), and ErbB4 (1.3%).