Low OD Value for Zero Standard in Competitive ELISA

Symptom

The zero standard (B0, representing maximum antibody binding without competing analyte) produces lower than expected optical density values, reducing overall assay sensitivity and dynamic range.

1. 1 Insufficient capture or detector antibody concentration
2. 2 Inadequate substrate incubation time
3. 3 Antibody binding affinity compromised due to suboptimal storage
4. 4 Substrate reagent expired or improperly stored

1. 1 Optimize and increase antibody concentration through titration experiments
2. 2 Extend substrate incubation time to allow sufficient color development
3. 3 Verify antibody storage conditions and prepare fresh working solutions
4. 4 Check substrate expiration date and ensure proper storage at recommended temperature

Related Video (3)

Bilibili (China-Accessible Mirrors) ★ 85

DuoSet ELISA — Sandwich ELISA Hands-on Protocol (Bio-Techne)

"Explicitly demonstrates capture and detection antibody application steps in sandwich ELISA, directly addressing the root cause of insufficient antibody concentration"

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R&D Systems Quantikine ELISA Operation Guide

"Official R&D Systems protocol video covers complete benchwork including antibody coating and application steps critical for achieving proper B0 signal"

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How to coat your own plate and run an Invitrogen ELISA kit

"Demonstrates plate coating procedure with capture antibodies, a foundational step where antibody concentration errors directly impact zero standard performance"