Reverse Image - White Bands on Dark Background

Symptom

Film shows 'bleached' or 'burnt-out' white bands against dark background instead of expected dark bands. Bands appear as negative images where high protein concentration exists.

1. 1 Excessive HRP-conjugated secondary antibody concentration causing substrate depletion
2. 2 Very high target protein concentration combined with high antibody levels
3. 3 Prolonged chemiluminescent substrate incubation with high HRP levels

1. 1 Reduce HRP-conjugated secondary antibody concentration (e.g., increase dilution 10-fold from 1:5000 to 1:50000)
2. 2 Decrease protein loading amount on gel to reduce target antigen concentration
3. 3 Shorten substrate incubation time or reduce primary antibody concentration

Related Video (3)

Cell Signaling Technology ★ 90

Western Blot Troubleshooting Guide

"Dedicated Western blot troubleshooting guide that would directly address the reverse image/high secondary antibody problem."

Bilibili (China-Accessible Mirrors) ★ 72

Western blot hands-on: Protein extraction through detection

"Hands-on protocol with explicit emphasis on troubleshooting common pitfalls, useful for understanding where secondary antibody concentration issues arise."

Bilibili (China-Accessible Mirrors) ★ 70

Western Blot — Full Protocol Walkthrough (Bio-Techne)

"Complete protocol walking through secondary antibody incubation and ECL detection, the exact steps where this failure originates."