A vacuum manifold for filtration microscopy includes a manifold top having multiple openings, and a capture membrane positioned above and spaced apart from the manifold top, where the capture membrane is configured to deflect into contact with a surface of the manifold top when a negative pressure is applied to the multiple openings. A method for filtration microscopy includes the steps of providing a vacuum manifold including a manifold top having a plurality of openings, and a capture membrane positioned above and spaced apart from the manifold top; applying sample drops to sample spots on the membrane, the sample spots positioned above the plurality of openings; applying a negative pressure to the openings such that the capture membrane contacts a surface of the manifold top; and optically imaging particulates on the capture membrane.