Chemicals for use in microscopy are delivered as ready-to-use prepared buffers that are conveniently packaged and made fresh for each order. Prepared microscopy buffers are economical and time-saving. In electron microscopy, phosphate buffers are preferred by many workers, partially because of the lack of toxicity compared with the second most commonly used buffer, sodium cacodylate. Phosphate buffers are best used either at physiological pH or in a slightly alkaline formulation.