Insufficient Signal from Zero Standard (B0)

Symptom

The zero standard (no competing antigen, maximum antibody binding) produces OD values that are too low, resulting in compressed standard curve with poor sensitivity.

1. 1 Antibody concentration too low to produce adequate coating or detection signal
2. 2 Insufficient substrate incubation time preventing full color development
3. 3 Antibody activity lost due to improper storage or freeze-thaw cycles
4. 4 Substrate reagent expired or improperly stored reducing enzymatic activity

1. 1 Increase coating antibody concentration by 1.5-2 fold or increase detector conjugate concentration incrementally
2. 2 Extend substrate incubation time from 15 minutes to 30 minutes monitoring color development
3. 3 Use freshly thawed aliquots of antibody stored at -20°C or -80°C avoiding repeated freeze-thaw
4. 4 Prepare fresh substrate solution immediately before use and verify substrate reagent expiration dates

Related Video (3)

Bilibili (China-Accessible Mirrors) ★ 78

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

"DuoSet hands-on video explicitly covers plate coating and capture/detection antibody steps where insufficient antibody concentration causes weak B0 signal."

Thermo Fisher Scientific ★ 72

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

"Coating-own-plate tutorial directly addresses antibody coating and titer issues underlying low zero-standard OD."

Bilibili (China-Accessible Mirrors) ★ 65

How to Run an R&D Systems Quantikine ELISA

"Quantikine walkthrough includes troubleshooting guidance useful for diagnosing depressed standard curve and weak signal."