THAWING

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A unit of glycerolized frozen red cells can be thawed using one of two methods: a) rapid immersion into a heated water bath maintained at 42 C for approximately 45 minutes; or b) by placement into one of the pouches of a plasma thawer maintained at 36 C for 35 minutes. Upon removal from the water bath or plasma thawer, the surface temperature of the red cells is measured using an infrared scanner or a NIST certified thermometer and should be between 30 and 34 C.

A. Water bath method

1. If using the waterbath, turn on the power switch located at the end of the water bath. Allow the water to warm to 42 C. This will take approximately 1 hour. Switch on the circulating pump in the water bath used to thaw the frozen red cells. Allow the pump to run for 1-2 minutes, then check the water temperature to ensure that it has stabilized at 42 C.

2. Using freezer gloves, remove the box containing the red cells from the freezer. Record the time on the eglycerolization Logsheet when the frozen red cells are placed in the water bath as the beginning of the deglycerolizing time period. Processing must be completed and the deglycerolized red cells must be placed in a 1-6 C refrigerator within 2 hours of removal from the -80 C freezer.

3. Open the freezing container and remove the unit of frozen red cells. Thaw the unit still in its plastic overwrap by immersing it in the water bath. Place lead weights on top of the units so that the units remain submerged during the thawing procedure.

NOTE: The thawed red cells inside the plastic overwrap should remain in the water bath until they reach a temperature between 30 and 34 C. This will normally take approx. 45 minutes.

4. Remove the unit from the water bath and check the temperature of the unit using an infrared scanner. If the temperature of the unit is not between 30 and 34 C, replace the overwrapped unit back into the water bath. As described above, recheck the temperature every 5 minutes until the desired temperature is achieved.

5. Remove the unit from the water bath and dry off the overwrap. Tear open the overwrap and discard it. Wrap the thawed unit loosely in a disposable white towel. Check the bag for any breaks by gently compressing the unit in the towel, wiping the entire bag surface with the towel and then inspecting the towel for blood stains. The presence of blood stains on the towel is evidence of bag breakage, and the unit must be considered contaminated. Units suspected of being contaminated should be disposed of in compliance with local Standard Operating Procedures for the disposal of liquid-stored blood products.

6. The thawed glycerolized red cells are now ready for deglycerolization.

B. Plasma thawer method

1. If using the plasma thawer, turn on the power to the plasma thawer and allow the system to warm to 36 C (+ 1 C).

2. Using freezer gloves, remove the box containing the red cells from the freezer. Record the time on the eglycerolization Logsheet when the frozen red cells are placed in the water bath as the beginning of the deglycerolizing time period. Processing must be completed and the deglycerolized red cells must be placed in a 1-6 C refrigerator within 2 hours of removal from the -80 C freezer.

3. Open the freezer container and remove the unit of frozen red cells. Remove the plastic overwrap and place the unit into one of the pouches of the plasma thawer.

NOTE: The thawed red cells without the plastic overwrap should remain in the pouch of the plasma thawer until they reach a temperature between 30 and 34 C. This will normally take approx. 35 minutes.

4. Remove the unit from the plasma thawer. Wrap the thawed unit loosely in a disposable white towel. Check the bag for any breaks by gently compressing the unit in the towel, wiping the entire bag surface with the towel and then inspecting the towel for blood stains. The presence of blood stains on the towel is evidence of bag breakage, and the unit must be considered contaminated. Units suspected of being contaminated should be disposed of in compliance with local Standard Operating Procedures for the disposal of liquid-stored blood products.

5. The thawed glycerolized red cells are now ready for deglycerolization.

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