optimal cutting temperature compound optimal cutting temperature compound optimal cutting temperature compound (oct compound) is used to embed tissue samples prior to frozen sectioning on a microtome-cryostat. this process is undertaken so as to mount slices (sections) of a sample onto slides for analysis. frozen section procedure: tissue embedded in optimal cutting temperature compound, mounted on a chuck in a cryostat and ready for section production components as stated on the bottle: 10.24% polyvinyl alcohol 4.26% polyethylene glycol 85.5% non-reactive ingredients"