Anti-Phosphothreonine Antibody - Western Blot. Mab anti-phosphothreonine antibody (clone 18F6) is shown to detect threonine phosphorylation of proteins in a lysate from A431 cells stimulated with EGF. Separation is achieved under reducing conditions using a pre-cast 4-20% iGel from Gradipore, Inc. A 1:1000 dilution of Mab anti-phosphothreonine is used for 30 min followed by detection using a 1:2500 dilution of IRDye 800 conjugated Goat-a-Mouse IgG [H&amp;L] ( and visualization using the Odyssey Infrared Imaging System developed by LI-COR. Other detection systems will yield similar results. IRDye is a trademark of LI-COR, Inc.