Application of pop-off method to bone marrow and peripheral blood specimens for purposes of electron microscopy.

In this paper, we describe a pop-off method applicable to the hematological field. Bone marrow or peripheral blood specimens from patients were placed on a clean glass slide and fixed immediately in 2% glutaraldehyde solution for 10 minutes. For the DAB reaction, the slide was immersed in the DAB reagent for 30 minutes, and post fixed with 1% OsO4 solution for 1 hour. Specimens on the slide were washed with buffer solution, dehydrated and polymerized directly on the slide. A gelatin capsule filled with Epon mixed monomer was then reversed over the specimen. After polymerization was completed, the specimen was popped off from the slide to the capsule and trimmed carefully to prepare for ultrathin sectioning. This method allows the entire sequence of tissue preparation to be carried out on the slide, from fixation to embedding, and even, especially in scanty specimens, including the DAB reaction. Electron microscopic findings in specimens prepared by this technique show excellent preservation and the absence of specific artifacts.