The disclosed methods for preparing cytological samples may include placing a cytological sample in a concave filter in a filtration system, applying a negative pressure to an outer side of the concave filter with a vacuum device to withdraw a liquid from the cytological sample, applying a sectionable matrix material over the filtered cellular material within the concave filter, and removing an assembly including the filtered cellular material and the sectionable matrix material from the filtration system. Various other related methods, systems, and materials are also disclosed.