An improved method of making tissue carriers for TEM and SEM fixation.

Hazards in fixing small pieces of tissue for electron microscopy include damage, drying, or loss. Over the years, microstrainer tissue carriers have been developed to minimize these problems. Construction materials have included glass tubing, copper grids for electron microscopy, stainless steel screen, and bolting silk (Padawer 1951, Friend 1963, Bronskill 1970). Carriers made from plastic embedding molds (e.g., BEEM capsules) with either TEM grids attached to the conical tip (Buchanan 1965) or Nitex screen cloth held to one end by a retaining ring have proven to be inexpensive and popular, though the former has a very small filtration area and in the latter small tissues may be lost or crushed between the screen cloth and the bottom rim of the carrier. This note describes a carrier in which Nitex is permanently sealed to the bottom edee of a BEEM capsule cylinder.