Abstract: An apparatus for freezing a biological sample having a frame, an enclosure adapted to conduct a cryogenic fluid therethrough, and a block in the enclosure such that the block is cooled to a temperature capable of freezing the sample. A force generating device is mounted on the frame generally above the enclosure. A sample holder is removably attached to the force generating device having a cavity at its free end for receiving a sample to be frozen. The force generating device, sample holder, and block are constructed to compress the sample between the block and the sample holder such that the holder penetrates the surface of the block and effectively seals the sample during compression.