Qbeads-Carboxyl Labeling Kit provides whole set of materials for researchers to bind the desired ligand onto magnetic beads conveniently. If only the ligand contain primary amine groups such as antibody, protein, or peptide, it can be conjugated to the magnetic beads easily. Qbeads-Carboxyl Labeling Kit comprises of the magnetic beads (Qbeads-Carboxyl) with surface functional group -COOH and all of the necessary reagents for labeling. The conjugated magnetic beads can be used for purification or depletion of biomolecules, immuoprecipitation, chromatinimmunoprecipitation, pull-down assay, and other applications.