These samplers provide a means for simple, fast microbiological analyses of environmental waters, cooling tower waters, process waters, laboratory grade and electronics waters, dialysis water, and food and beverage products. Each sampler is constructed to combine both an intimate contact of a 0.45 ?m membrane filter to a nutrient-pad, and the incorporation of an air-vent on the upper back portion of the paddle. This configuration allows for the draw-through of 1 mL of sample to affix microorganisms to the filter surface for subsequent culturing within its transparent plastic case. The filter is grid-marked to aid in counting the microbial colonies grown on its surface. Each sampler assembly is packaged in a sealed plastic envelope.