Novel Use of Pipette Based Capsules for Glycol Methacrylate, Methyl/Butyl Methacrylate and Epoxy Resin Processing with Mouse Tissue That Reduce Processing Solution Volume and Time.  

Authors: Philip Seifert, HTL(ASCP), Xinyao Hu, Bianai Fan and Darlene A. Dartt, PhD, Schepens Eye Research Institute of Mass Eye and Ear, Boston, MA

The mPrep/S capsules (Microscopy Innovations) are customized pipette tips with screen inserts designed for various electron microscopy applications. Capsule processing methods were developed for mouse ocular and mineralized bone for histology and transmission electron microscopy (TEM) applications and compared to manual and carousel processed methods. The novel methods tested enable processing larger sized tissues (~3 mm diameter) including whole, anterior or posterior segments of mouse eyes and optic nerves within a single capsule that use 75% less reagents and time. Capsule processed tissue embedded in Glycol Methacrylate, methyl methacrylate/butyl methacrylate and EMBED812 epoxy resin were sectioned for histological staining including H&E, toluidine blue, osmium-paraphenylenediamine, Von Kossa and TEM imaged. Stained slide scanned micrographs and TEM images from capsule processed samples were measured and compared to conventional processed using a carousel processor or manual processing.  There were no detectable differences in tissue preservation, staining, optic nerve axon density or processing related artifacts in any of the tissue processed into the resins.  Use of capsules with pipette propelled mixing delivers accelerated diffusion of reagents and infiltration of embedding media into specimens that decreases both processing volume and time compared to manual or carousel processing.  A variety of embedding media resins may be used with capsules for histology and electron microscopy tissue processing.