Method and assay devices for the detection of the presence or amount of biological material, analyte(s), or microorganism(s) in a sample. The method includes the steps of liquefying the sample (if necessary) and distributing the liquefied sample over the surface of the assay device. The device may comprise an incubation plate, a dip stick device, or other devices. The devices have at least one reagent provided within the devices. Some devices have a generally flat horizontal surface which is divided into a plurality of recessed wells. Others have one or more surfaces with reagent island(s) immobilized thereon. Each well or reagent island is adapted to hold an aliquot of liquid. The wells or reagent islands are sized and shaped, and formed of a suitable material, to hold the aliquot within the well or reagent island by surface tension. Any excess liquid from the liquefied sample is drained from the surface of the device. The method then involves incubating the assay device until the presence or amount of the biological material, analyte, or microorganism is determined.