Mouse-on-Mouse (MOM) Background

Symptom

High background staining when using mouse primary antibody on mouse tissue. Secondary antibody binds endogenous mouse IgG throughout the tissue, creating non-specific signal.

1. 1 Secondary antibody raised in same species as sample tissue (e.g., anti-mouse secondary on mouse tissue)
2. 2 Secondary antibody binds endogenous IgG present in tissue sections
3. 3 No secondary-only control performed to identify source of background

1. 1 Switch to primary antibody raised in different species (e.g., use rabbit antibody like α-Smooth Muscle Actin D4K9N #19245 instead of mouse antibody on mouse tissue)
2. 2 Use species-matched detection reagent for alternative primary (SignalStain Boost #8114 for rabbit primary eliminates MOM background)
3. 3 Always include control slide stained without primary antibody to confirm secondary antibody is source of background
4. 4 If mouse primary is essential, perform biotin block after normal blocking and before primary antibody incubation

Related Video (3)

Bilibili (China-Accessible Mirrors) ★ 95

Immunohistochemistry on Paraffin-Embedded Sections (CST Demo)

"CST-based paraffin IHC protocol demonstration directly covers the technique where MOM background occurs and provides proper procedural context."

Cell Signaling Technology ★ 90

Immunohistochemistry Protocol for Paraffin embedded Tissue Sections

"CST's official IHC protocol video for paraffin sections includes guidance on antibody selection and background troubleshooting relevant to MOM problems."

Cell Signaling Technology ★ 72

Better IHC Step 1: Antigen Retrieval

"Focused antigen retrieval optimization video addresses upstream IHC variables that can exacerbate background issues and complement understanding of the full workflow."