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Species on Species Detection

When your primary antibody is the same species as your specimen

When an unconjugated primary antibody is made in the same species as your tissue specimen, subsequent detection using a secondary antibody usually generates high background staining and interference due to the inability of the secondary antibody to distinguish between the primary antibody (immunoglobulin) and endogenous immunoglobulins. This high background obscures target antigen specific staining and often leads to false positive staining.

Vector Laboratories offers solutions for two often encountered species on species scenarios:

M.O.M.® (Mouse on Mouse) Kits

Our Mouse on Mouse kits significantly reduce endogenous mouse Ig staining when applying mouse antibodies on mouse specimens (e.g. tissue sections and cell preparations). Additionally, these kits:

  • Contain proprietary M.O.M. Mouse IgG Blocking Reagent
  • Employ either avidin-biotin or polymer technology
  • Are compatible with fluorescent or enzyme-based detection
  • Are available with or without enzyme or fluorochrome


H.O.H.™ (Human on Human) Immunodetection Kit

Our H.O.H. Immunodetection Kit (HOH-3000) significantly reduces endogenous human Ig staining when applying human (or humanized) primary antibodies on human tissue sections. Additionally, this kit:

  • Is a comprehensive HRP (peroxidase) kit with volume matched reagents and ImmPACT DAB EqV substrate
  • Does not require tedious antibody dilution calculations
  • Enables staining results in about 90 mins following initial preparation
  • Provides essentially background-free staining on frozen and paraffin-embedded human tissue sections
Hoh Image

LEFT image: Serial sections of human kidney (FFPE) showing strong, specific staining (brown regions) using human anti-cytokeratin primary antibody detected with HOH-3000.

RIGHT image: Negative control. Serial sections of human kidney (FFPE) showing an absence of staining (no background) with the omission of the primary antibody in the HOH-3000 assay.
Note: Both sections counterstained with hematoxylin (blue nuclei).

LEFT image: Without M.O.M. Mouse intestine stained with standard anti-mouse Ig polymer system and Vector DAB Substrate. Hematoxylin counterstain. Note background IgG staining.

RIGHT image: With M.O.M. Mouse intestine stained with Vector M.O.M. Vector ImmPRESS Kit, Vector DAB and no primary antibody.

Explore Species on Species Detection

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Mouse on Mouse (M.O.M.®) Kits are specifically designed for detecting and visualizing (unconjugated) mouse primary antibodies in mouse tissue specimens. These kits contain a proprietary reagent that blocks endogenous mouse Ig in specimens therefore preventing non-specific binding of subsequent anti-mouse IgG detection reagents.

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The H.O.H. Immunodetection Kit is intended to detect human (or humanized) antibodies on frozen or paraffin embedded human tissue sections. This kit employs a straightforward two-step primary antibody preparation followed by standard IHC assay detection procedures to eliminate confounding interference from endogenous human IgG.


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