Disclosed is method of improving flow of a liquid sample in an assay device, as well as a method of performing an assay on a liquid sample for the detection of one or more analytes of interest. The methods use the addition of a reagent, such as a wash reagent, to wet the fluid flow path of a sample prior to sample addition, thereby improving flow of the sample through the fluid flow path that has been wetted as opposed to flow of the sample through the fluid flow path that has not been wetted. The reagent wets the fluid flow path between the sample addition zone and the wicking zone.