A microphase separation-based porous polyvinylidene fluoride (PVDF) membrane has been generally used for immobilizing proteins in a Western blotting procedure. The conventional PVDF membrane is extremely hydrophobic and will not wet in aqueous solutions unless pre-wetted with methanol. In addition, long-term immersion of the PVDF membrane in methanol deteriorates both its protein binding capacity and mechanical strength. This study showed that a PVDF membrane consisting of long nanofibers, which were prepared by electrospinning and subsequent calendering, was mechanically strong with uniform and opened pores. This membrane exhibited high sensitivity, low background and high binding capacity for the detection of protein bands without a methanol pre-wet step. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.