A wick for use in determining sufficiency of an amount of analyte fluid provided to an analyte test section of an assay device is provided. The wick comprises a primary wick portion attached or attachable to the analyte test section so as to be in fluid communication therewith. The primary wick portion has a receiving surface adapted for receiving the analyte fluid and is configured to draw the analyte fluid from a first area to a second area of the primary wick portion. The assay wick further comprises an indicator portion having a contrasting visual characteristic. The indicator surface is covered by at least a portion of the primary wick portion, which comprises a wicking material that becomes more light transmissive when wetted by the analyte fluid. The contrasting visual characteristic is viewable through the at least a portion of the primary wick portion only when the at least a portion of the primary wick portion is suffused by the analyte fluid.
