As part of the Signal-Seeker? product line, phosphotyrosine affinity beads have been optimized to detect endogenous levels of phosphotyrosine modified proteins, which often represent <1% of the target protein. Phosphotyrosine affinity beads comprise an anti-phosphotyrosine antibody (Clone 27B10) that has been chemically conjugated to Protein G beads. Validation studies have shown that these beads can immunoprecipitate a wide range of phosphotyrosine proteins without detectable leaching of either heavy or light chains in an IP assay. A comprehensive Signal-Seeker? Phosphotyrosine Detection Kit is also available (BK160) and is recommended for first time users.