Some common mistakes can happen while using a laboratory freeze dryer for lyophilization. The solutions to avoid such kinds of basic mistakes are provided here:
Usually, a specimen is kept in a freeze dryer without the consideration of its compatibility with the dryer and its specifications. This can lead to a decrease in the quality of the dried sample and expensive damage to the dryer. So it’s important to identify the components of the sample and their requirements for lyophilization.
The collector temperature of a freeze dryer should be between 15°C to 20°C below the freezing point of a sample, so having a general estimation of the eutectic temperature of your sample is important. This is important for keeping the specimen solidified amid drying and to trap the lyophilized vapor before vacuum siphon.
Ensuring the size of the collector is big enough to accommodate the volume of the sample load is a must. Ceasing the run and defrosting the collector is not an ideal choice, thus using a collector that is larger than the base size causes no harm.
Different samples may contain compounds that require special components in the freeze dryer to contain
- Acids: Polytetrafluoroethylene (PTFE) coatings protect stainless steel coils and collectors.
- Solvents: glass lids are used when a solvent harms acrylic lids.
- Particulates: Inline HEPA filters are placed between the collector and the vacuum pumps to shield the siphon from damage from particulates.
Vacuum Pump Damage
Maintaining and keeping up a profound vacuum level has to be one of the main issues in freeze-drying in laboratories as non-collected vapors may enter the vacuum pump. Here are some suggestions to prevent that from happening
- Start-up Sequence: Make sure that your collector coils have cooled to at least -40°C before the pump is started to prevent vapors from entering. A cleanse valve will allow the oil to heat up before the system pulls down thus preventing vapor condensation.
- Shut Down: The pump should be allowed to operate with the gas ballast open for 20-30 minutes after a run which helps any condensed vapor to leave the pump.
- Maintenance: Using flushing fluid to rinse away any contaminants within the pump, keeping the oil in check will help you immensely in maintaining your pump.
This is where Harvest Right freeze dryers ensure the quality of your specimens and provide you with better cooling.