The present invention provides a device in a multiwell plate that allows
for one to obtain substantially all of the liquid that has flowed through
the filter thereby reducing hold up volume. This is accomplished by
forming at least one hydrophobic area in the hydrophilic filter in each
well. After the filtration has occurred, air is allowed to enter the
underdrain of the plate through the hydrophobic area(s) which causes any
residual fluid held by surface tension to be released and to flow out of
the underdrain to the outside environment.