High-pressure freezing

High pressure freezing (HPF) is a sample preparation method in which a small sample is frozen under very high pressure. When done successfully, the water in the sample is frozen in a glass-like state, without the formation of ice crystals. This results in an excellent structural preservation of the sample.

The GI department has two high-pressure freezers:

• EMPACT (Leica)
• HPM100 (Leica)

Comparison of EMpact vs HPM100

• The HPM100 is better for thick samples.
• On the EMpact the waiting time between shots is shorter:
  • Higher throughput of sample prep
  • Allows for time-coarse experiments
• The EMPACT is smaller, lighter, and can be partially disassembled, and thus is more mobile.
• In the EMPACT the samples are physically enclosed inside sample shuttles. Therefor you can use this machine for freezing GMO’s or infectious agents (as long as the EMpact is inside an appropriate lab space and appropriate permissions are obtained). In the HPM100 the samples are not physically contained and therefor the machine can only be used for harmless or fixed/inactivated samples.