Agar may be used as a support medium for cell samples (see agar embedding in EM pages). It may also be used to maintain specimen orientation for small samples, in which case a 2% solution should be used. Small blocks of agar are prepared in a ice tray and are cut into slices, a slit is made in one face and the specimen is inserted into it. One face of the agar block may be marked with Indian ink or the block can be cut in an irregular shape to indicate the correct orientation. The agar block containing the tissue sample can then be processed and cut as a normal specimen.