Use of LR white embedding medium for routine transmission electron microscopy

Most current EM embedding media require component mixing prior to use. Also, many epoxy resins are carcinogenic and can present significant health hazards in the unpolymerized form. LR White acrylic embedding resin(by London Resin Co.; available Fullam, Pelco, Polaron etc.) is a one component, extremely low viscosity resin. The resin, according to Mfr. has a very low toxicity both in monomeric and polymerized states. We have found no skin sensitivity specifically known to be related to the resin over a period of 1 yr routine resin use. The cold cure accelerator does have some toxic risk, and contact with skin and eyes should be avoided. Accelerator, however, is not used for thermal curing. Because of resin advantages, the purpose of this study was to determine routine TEM methods consistent with LR White resin use for a variety of sample types(fungal, plant, and animal).