Free-swimming bacteria of the genus Spirillum are clearly resolved by a replica Leeuwenhoek microscope, using a single lens as magnifying component.
A colony of Microspora cells, with all the apperarance of viability, was seen in a reconstituted algal specimen originally sent to London by Leeuwenhoek in the 17h century.
The truffle, Tuber melanospora, has spores with spiny projections of bacterial dimensions. They are clearly resolved by the Leeuwenhoek lens.
A single lens - like Leeuwenhoek's original microscope - resolves the tripartite structure of a human spermatozoon.