This kit is designed for enrichment of polyubiquitinated cellular proteins conjugated with lysine 63 using GST-TAB2 (NZF). Polyubiquitinated proteins bound on GST-TAB2 (NZF) can be precipitated using glutathione resin and then eluted by a buffer containing 10 mM glutathione. Polyubiquitinated proteins can be assayed by immunoblotting or mass spectrometry