Josef Blum at Sorvall Porter-Blum microtome, 1953
The MT-1 was the first commercial version of the mictrome shown on the photograph. In this version, the tissue block is advanced to the knife by a mechanical device controlled by a knob that can vary section thickness from 25 to 500 nanometers.
Courtesy of Boeckeler Instruments Inc., RMC Products Group
Porter-Blum microtome, exhibit, library