Local blank patches / air bubble imprints

Symptom

Certain regions of the membrane show no signal at all, forming round or irregular blank zones; often due to transfer failure in those areas while surrounding bands look normal.

1. 1 Air bubbles trapped between gel and membrane during transfer
2. 2 Filter paper or sponges were not fully soaked
3. 3 Transfer sandwich was shifted or seated unevenly
4. 4 PVDF membrane was not properly pre-treated (not methanol-activated)

1. 1 When assembling, use a roller or a pipette to gently push out all air bubbles
2. 2 Fully pre-wet all transfer consumables (paper, sponges) in transfer buffer
3. 3 Check membrane and gel orientation; ensure they are properly aligned
4. 4 Activate PVDF in methanol for ≥15 seconds, then equilibrate in transfer buffer

Related Video (3)

Cell Signaling Technology ★ 55

Western Blotting Protocol

"Full protocol video showing transfer steps where proper bubble-free assembly can be observed, useful for learning correct technique."

Cell Signaling Technology ★ 82

Western Blot Troubleshooting Guide

"Dedicated Western blot troubleshooting guide that likely covers transfer failures such as air bubble-induced blank patches and how to prevent them."

Bio-Rad Laboratories ★ 78

Quick Tips: Evaluating Western Transfers using Stain-Free Gels and Bio-Rad Imaging System

"Demonstrates evaluating Western transfers, directly addressing how to detect transfer failures like blank regions before or after immunodetection."