Three types of membranes were evaluated on the basis of substrate color retention, durability, and ease of use.
The PVDF membranes proved superior for use in the CLI. Antigen transfer from the petri plates or filter membranes was possible only once the PVDF membranes were moistened with 100% methanol, which temporarily neutralized the hydrophobic properties of the membrane.This membrane phenomenon greatly in creased the efficiency of the CLI protocol, as many membranes could be processed in the same reaction chamber without antigen cross-contamination between the membranes. Because the PVDF membranes were easy to use, were much more durable than the nitrocellulose membranes, and had better color re- tention than the Zeta-Probe membranes, the PVDF mem- branes were used for optimizing the CLI procedure.