Many histologists use forceps and other tools to help them manipulate and position tissue specimens in the desired arrangement. Histologists often have individual preferences for the size and shape of their forceps. It is recommended that all forceps be wiped well between specimens to prevent carry-over contamination from cassette to cassette, also known as "forceps metastasis." Forceps without "teeth" or small grooves at the tip will also help prevent carry-over.
Tissue tampers or stampers can apply pressure evenly on the specimen to help flatten it so it will harden in one flat plane as the block solidifies. Making specimens as flat as possible about the block face is essential to obtain a single, representative section of the specimen. Forceps and other tools used to manipulate tissue during orientation must be kept warm so that tissue fragments do not adhere to tools, as the paraffin on them will begin to solidify on the surface if they are too cool. Slight warming wells are found in most embedding units to keep tools at the necessary temperatures. These wells should be cleaned as frequently as any tools used during embedding, as they can harbor small tissue fragments that can then be transferred to adjacent specimens.
