Protein Blocking Solutions

Non-specific protein interactions between detection reagents and target protein elements can cause unwanted background staining. To minimize this type of interaction, use an appropriate protein blocking reagent:

  • Normal sera — widely used as a general protein block in tissue and cell-based staining. For best results, choose a serum species for blocking that matches the species of the secondary antibody.
  • Carbo-Free Blocking Solution (SP-5040) - for lectin staining or use in multiplex IHC applications. Lectins are used for at least one label because this solution does not contain interfering glycoproteins.
  • BSA (SP-5050) — Our BSA is free of the glycoproteins and impurities that are present in other grades of BSA and can introduce artifacts or increase background staining. For use in IHC, iCC, IF, blots, and ELISA applications.
  • Animal-Free Blocker, 5x Concentrate (SP-5030) is a plant-derived agent and diluent for immunohistochemistry, nucleic acid and protein blotting, and other applications. It contains no animal-derived protein and can be used as an alternative to sera, BSA, casein, or non-fat dry milk.
  • R.T.U. Animal-Free Block and Diluent (SP-5035) — plant-protein derived universal antibody diluent and protein blocking reagent for use in multiplex IHC applications where primary or secondary antibodies from multiple species are used. This solution does not contain animal immunoglobulins, which may be non-specifically bound by the secondary antibodies.
Prostate without and with R.T.U. Animal Free Block and Diluent used in the blocking step. Both sections are no primary antibody controls with Biotinylated Universal Secondary Antibody, VECTASTAIN® Elite® ABC, and Vector DAB Substrate for detection. Note significant toning in section without RTU Animal Free Block and Diluent.

Resources

Immunohistochemistry Resource Guide

The Immunohistochemistry Resource Guide will help you navigate through the many choices of detection systems, substrates, and ancillary reagents that complete your workflow.
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IHC Troubleshooting Guide for ABC Systems

A quick reference guide that outlines the systematic controls to help identify background sources in an immunohistochemistry protocol using ABC systems.  Also troubleshoot issues of weak or no staining. Laminated.

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IHC Troubleshooting Guide for Polymer Kits

A quick reference guide that outlines the systematic controls to help identify background sources in an immunohistochemistry protocol polymer detection systems.  Also troubleshoot issues of weak or no staining. Laminated.

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