Made of acetal polymer, disposable plastic tissue cassettes are suitable for holding and identifying tissue samples in processing, embedding, and sectioning procedures. The cassettes fit securely in microtome chuck adapters. They are molded from a high density polymer that is totally resistant to the chemical action of histological solvents. These cassettes are designed to accept standard metal lids (cat.# M481) and will keep specimens in complete safety during processing. The slanted writing surface accepts markings easily, permitting sample identification throughout all stages of embedding and long afterwards when in archives. They are available in 11 colors.