The UbiQapture-Q Kit facilitates isolation of mono- and poly-ubiquitinylated proteins (independent of lysine residue chain linkage) from cell extracts, tissue lysates and in vitro assays through the use of a high-binding affinity matrix. Captured proteins can be analyzed by Western blotting using the ubiquitin-conjugate specific antibody provided, using antibodies to specific proteins of interest, or eluted from the matrix for subsequent biochemical characterization. The matrix supplied with the kit has superior binding characteristics and is comparable with a wide range of lysate buffers and cell/tissue samples from a variety of species. Material provided is sufficient for 25 binding assays.