A specimen carrier for processing large numbers of biopsy materials for epoxy embedding and electron microscopy is described. Commercially available 18-mesh stainless steel or 16-mesh aluminum wire screening is used. The screening is cut into 1 × 3-inch strips. One corner is snipped off for orientation purposes. Four drops of warm 4% agar is placed on a prewarmed standard microscopic glass slide. A thin agar support film is formed on the bottom side of the horizontally held wire screen by lightly running it against the agar. Tissue blocks trimmed to 1 mm3 are blotted on filter paper and placed in a prearranged order on the top surface of the support film. A thin top coating of agar is applied on the specimen by touching it with the tip of a pasteur pipette containing warm 4% agar. The agar-screen unit with the mounted specimens is stabilized in 4% buffered formalin and rinsed with Sorenson's phosphate buffer, pH 7.4, with 6.8% sucrose. It is then processed as a unit through routine osmium tetroxide postfixation, alcohol dehydration, and Epon 812 infiltration. The tissue blocks are plucked off the agar support film with fine-tipped tweezers and embedded in individual capsules. No difficulty in thin sectioning was encountered and examination of the sections under the electron microscope showed good infiltration by the epoxy resin.
ASJC Scopus subject areas
- Medical Laboratory Technology