G-Biosciences' HOOK™ HRP SULFO and HRP PLUS Labeling Kits are high efficiency enzyme labeling kits for tagging proteins with the horseradish peroxidase enzyme

G-Biosciences' HOOK™ HRP and AP SULFO Labeling Kits have activated HRP and AP, respectively, which couple to peptides, proteins and ligands that have free sulfhydryl groups. The maleimide activated HRP and AP save several hours of valuable research time, as the first step of what is normally a two-step maleimide activation procedure has already been completed. The HOOK™ HRP PLUS kit has an activated HRP that couples with high efficiency (greater than 90 percent) to the numerous amine groups of proteins. This is superior to the commonly used glutaraldehyde coupling chemistry.

To aid in the preparation of HRP and AP conjugates using free sulfhydryls, the HOOK™ HRP and AP SULFO kits are supplied with SATA (N-Succinimidyl S-acetylthioacetate), which adds free sulfhydryls to existing amine groups, and 2-mercaptoethylamine·HCl, a mild reducing agent for conjugating HRP and AP to immunoglobulin G (IgG) and its fragments.

G-Biosciences' HOOK™ HRP and AP SULFO Labeling Kits are supplied with their Tube-O-Reactor™ system, which allows all the key steps of enzyme labeling of proteins to be performed in a single tube. This minimizes the risk of sample loss, experimental time and hands-on phases. Enzyme labeling involves three main steps that can all be performed in the supplied Tube-O-Reactor™: 1. Equilibration of reaction conditions for optimized reactions; 2. Subsequent reaction of maliemide activated enzyme with target proteins; 3. Removal of unreacted agents and by-products.

G-Biosciences' HOOK™ HRP PLUS Labeling Kit uses HRP that has been activated by the addition of reactive aldehydes (HRP PLUS). The aldehyde groups react spontaneously and at high efficiency with primary amines, located at the N-terminus of proteins or in lysine residues, to form intermediate Schiff Base complexes. In turn, these are selectively reduced by the supplied reduction agent. Following quenching of the reaction, the protein is linked to the horseradish peroxidase enzyme by stable amine linkage. The labeled protein or antibody can now be used for immunoblotting, ELISA and histochemical techniques. The HOOK™ HRP PLUS Labeling Kit is supplied with G-Biosciences' JAW™ Dry Buffer packs for convenient PBS and Carbonate-Bicarbonate buffer preparation. The activity is 120 to 200 units per milligram.

The HOOK™ AP SULFO kit is for tagging proteins with the alkaline phosphatase enzyme.