"Spare me the analysis, Mr. Spock, please? It's enough that it works."
A microscope was a scientific instrument designed to allow the viewing of things too small to be seen by normal Human vision. It used a system of lenses and mirrors to magnify an object many times more than it actually was.
Klingon scientist Antaak used a microscope during examinations he conducted. At one point in 2154, Phlox used Antaak's microscope to see Augment DNA was present in a particular Klingon virus. (ENT: "Affliction")
In a laboratory on Earth Two in 2266, Doctor Leonard McCoy used a microscope to analyze tissue samples from diseased members of a landing party which was visiting the planet and included himself. At one point, Spock, who was also in the landing party, referred to the microscope as "a museum piece" and started to describe its specifications, though McCoy interrupted him with an irritated request to be spared the analysis, simply satisfied that the apparatus worked. (TOS: "Miri")
In 2370, Lieutenant Commander Data created a microscope using multiple lenses when he was stranded on Barkon IV, a planet with a pre-warp civilization. Data's impetus for creating the device was to use it to research radiation sickness that was spreading among the planet's inhabitants. (TNG: "Thine Own Self")
Lieutenant Jadzia Dax used a microscope, which was combined with a probe analyzer and a computer display, to search a probe she had taken from under Rao Vantika's fingernails. Dax found a microscopic generator Vantika had used to transfer his consciousness into another person shortly before he died. (DS9: "The Passenger")
Captain Kathryn Janeway kept a six-hundred-year-old microscope among the decoration of her ready room on board the USS Voyager. Her grandfather had gifted it to her during her childhood. (VOY: "Caretaker", "Parallax", "The Cloud", "Eye of the Needle", "Ex Post Facto", "Prime Factors", "Hunters", "Counterpoint")
- Microscope laser
- Nano-imaging camera
- Portable electronic microscope
- Proton microscope
In the first draft script of TOS: "Charlie X", a microscope was used by Captain Kirk. However, in a memo from Robert Justman to Gene Roddenberry (dated 7 June 1966), Justman suggested omitting the microscope, commenting, "I wish we could [...] as I don't want to have to design and construct what would appear to be a microscope of the future."
Senior Illustrator Rick Sternbach made a sketch for an electronic microscope for use by Doctor Bashir in the Star Trek: Deep Space Nine episode "Vortex". The prop was not built but Sternbach showed the sketch in the DS9 Season 1 DVD special feature "Deep Space Nine Sketchbook".