The ImmPRESS®️ polymerized reporter enzyme staining system uses novel conjugation and micropolymer chemistries to create a highly sensitive, ready-to-use, one-step, biotin-free detection system. This unique micropolymer of highly active enzyme (peroxidase or alkaline phosphatase) is attached to our affinity purified secondary antibodies, producing reagents with outstanding sensitivity and low background.
The peroxidase micropolymers of the ImmPRESS®️ HRP polymer reagent limit steric interference and provide enhanced accessibility to the target, avoiding the disadvantages of other polymer systems that use large dextrans or other macromolecules as backbones. The result is crisp, strong staining of antibody targets, especially nuclear and membrane antigens (such as Ki67, estrogen receptor, bcl-2, CD3, CD8 and CD10) and greater sensitivity than other polymer systems.
Key advantages of the ImmPRESS®️ Polymer System:
Enhanced accessibility to nuclear and membrane antigens
Ready-to-use in a convenient dropper bottle
Shorter assay time
Simplified multiple labeling
The staining procedure is simple as shown in the diagram below. Following a blocking step with the diluted normal horse serum, sections are incubated with primary antibody. After a brief wash, the appropriate ImmPRESS®️ Reagent is added to the sections and incubated for 30 minutes. Sections are again rinsed and the slides are developed with the peroxidase substrate of choice.
Consider Species Cross-Reactivity
When choosing the optimal detection system for your application, it is important to consider not only the species of the primary antibody but also the species of the tissue. If the species of the primary antibody and the species of the tissue are closely related (e.g. rat and mouse), the secondary antibody may bind to endogenous IgG in the tissue section leading to background. The following options minimize background staining in these instances:
Use a secondary antibody specifically adsorbed to remove cross-reacting antibodies of closely-related species (e.g. ImmPRESS®️ Anti-Mouse IgG, Rat Adsorbed).
Use the M.O.M. ImmPRESS®️ Kit (Cat. No. MP-2400) for applications of mouse primary antibodies on mouse tissue.