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 IHC protocol on paraffin-embedded tissue sections directly matches the failure context and covers the complete workflow where MOM background occurs"

Cell Signaling Technology ★ 88

Immunohistochemistry Protocol for Paraffin embedded Tissue Sections

"Official CST IHC protocol video for paraffin-embedded sections provides foundational technique instruction to prevent the described background staining issue"

Cell Signaling Technology ★ 72

Better IHC Step 1: Antigen Retrieval

"Focuses on optimizing IHC staining quality and troubleshooting fuzzy results, directly relevant to understanding and preventing non-specific background"