Portable electronic microscope
A portable electronic microscope was a piece of 23rd century medical technology designed for use in analyzing microorganisms.

In 2266, a landing party from the  which had become stranded on the surface of a planet whose population had been devastated by a plague, utilized such a microscope in combination with a biocomputer in an attempt to analyze and find a cure for the virus, with which they had all been infected. ()

See also 
 Microscope

de:Elektronenmikroskop
Medical equipment