Ultra-low temperature (ULT) Freezers have been integral to laboratories, hospitals, research facilities, and most importantly, blood banks. The special freezers are designed and developed to maintain extremely low temperatures, mostly ranging from -40°C to -86°C.
This way, it ensures that such valuable biological samples, including blood products critical for transfusion and required for research, are kept for future use.
Two very important aspects that are the basis for the proper functioning and long life of this indispensable piece of equipment are proper defrosting and proper maintenance at regular intervals. The following is an overview of the importance of defrosting and procedures for maintaining an ultra low temp freezer, with an emphasis on storage in blood banks.
Importance of Defrosting Ultra-Low Temperature Freezers
As time accumulates, so will the ice inside the ultra-low temperature freezer compartments, and this will present several problems that work towards the workability of the freezer and integrity of samples stored.
1. Temperature Uniformity: In the freezer, airflow might be interfered with by the formation of ice, thereby resulting in temperature variation. This would be followed by incomplete or irregular storage conditions, hence sensitive samples lose their viability.
2. Reduced Efficiency: When this forms on the evaporator coils, the ice reduces the cooling capacity of the freezer. The compressor has to work extra hard to be able to maintain the set temperature, hence more consumption of energy and possible mechanical breakdowns.
3. Sample Integrity: Samples may not be protected if, in case of a power failure or malfunction, the freezer builds up an enormous amount of ice. This could be very alarming if it was in the blood bank, where the products of blood should be maintained.
Defrosting Procedures for Ultra-Low Temperature Freezers
Otherwise, the ultra-low temperature freezer would simply end up not functioning at its best because in time, a layer of frost would thicken over the evaporator. To avoid such problems and enable the ultra-low temperature freezers to always work at peak efficiency, they need to be subject to periodical defrosting. The period, however, will be subject to different kinds of variables.
Steps for Defrosting:
1. Preparation:
– Disconnect the power supply to the freezer to prevent accidents during the defrosting process.
– Place towels or absorbent materials around the base of the freezer to catch melting ice.
2. Emptying the Freezer:
Remove all samples, racks, and shelves from the freezer and place them in the temporary storage unit with a similar temperature range.
– Carefully label and organize the samples to ensure proper re-storage after defrosting.
3. Thawing the Ice:
– Leave the freezer door open to allow the ice to melt naturally.
– Never use sharp objects or excessive force to remove ice, as this can damage the interior surfaces.
– Defrosting may be sped up by the use of fans or shallow trays of water in the room, both at room temperature, placed in the freezer.
4. Cleaning the Interior:
– Defrost the freezer. Clean the inside surfaces of the box with suitable mild detergent or disinfectant for freezers.
– Thoroughly dry the interior to prevent mold or bacterial growth.
5. Restoring the Freezer:
– Once the interior is clean and dry, return the shelves, racks, and samples to their original positions.
– Reconnect the power supply and allow the freezer to reach the set temperature before restocking sensitive samples.
Maintenance Practices for Ultra-Low Temperature Freezers
Besides, defrosting is part of the routine maintenance care for the ultra-low-temperature freezers and is quite paramount, especially in blood bank storage settings.
1. Temperature Monitoring:
Strong temperature monitoring system to be put in place with alarms signaling any change of temperature.
– Regularly calibrate temperature sensors to ensure accuracy.
2. Door Seal Checks:
– Inspect the integrity of the door seals regularly to ensure a tight closure.
– Clean the seals with a mild detergent to remove any debris that might interfere with the seal.
3. Condenser Cleaning:
– Dust and debris can accumulate on the condenser coils, reducing cooling efficiency.
– Clean the condenser coils with a soft brush or vacuum cleaner to remove dirt and maintain optimal airflow.
4. Routine Inspections:
– Conduct regular visual inspections of the freezer’s exterior and interior for signs of wear, damage, or leaks.
– Address any issues promptly to prevent further damage or loss of samples.
5. Power Supply Backup:
Consequently, great care should also be taken to install an extra back-up power supply, for instance, UPS (Uninterruptible Power Supply), to avert temperature fluctuations when such out
6. Staff Training:
– Train laboratory staff on proper freezer usage, defrosting procedures, and emergency protocols.
– Create a maintenance schedule and ensure all staff are aware of their responsibilities.
Ultra-Low Temperature Freezers in Blood Bank Storage
Proper defrosting, maintenance, and an ultra-low freezer are an added asset to the blood bank for the protection of its integrity. The blood components in red cells, platelets, plasma, and cryoprecipitate are stored at a few specific temperatures required for their quality and efficacy.
1. Red Blood Cells (RBCs): – Stored at temperatures between 1°C and 6°C for standard blood bank refrigerators. Ultra-low temperature freezers are also available for long-term storage of rare blood types or for longer periods at low temperatures.
2. Platelets: – Stored at room temperature with agitation to prevent clotting for short periods. – Ultra-low temperature freezers are used for cryopreservation of platelets at -80°C for long-term storage.
3. Plasma: – Fresh Frozen Plasma (FFP) is stored at -18°C to -30°C. – Cryoprecipitated Antihemophilic Factor (Cryo) is stored at -18°C to -30°C or -80°C for extended storage.
4. Cryopreservation: Ultra-low temperature freezers are essential to keep the cryopreserved products, including stem cells, bone marrow, and specialized blood components stored for long durations.
Conclusion
In summary, proper defrosting and maintenance of ultra-low temperature freezers are supreme in the aspect of biological sample preservation, especially in the applications of blood bank storage. Regular defrosting will remove the danger of ice build-up, which may jeopardize the temperature uniformity and, therefore, sample integrity. Other practices on the maintenance include temperature monitoring, checking on the door seals, cleaning of the condenser, and at the same time, ensuring the services required from these devices are delivered with high reliability and performance.
It has become imperative that blood bank set-ups have an ultra-low temperature free freezer to store the blood products in a manner that retains the quality and efficacy of the products for safe transfusion and medical research. This will, therefore, ensure that guidelines toward strict defrosting and maintenance are followed in a manner to ensure that the interest of sample preservation, and ultimately patient care, remains top in laboratories and blood banks.
