Thawing Instructions

VIL recommends that the following instructions be strictly followed when thawing a bag of Hypermune® Equine Plasma.

IMPORTANT: Maintain the water temperature at approximately 40° C. A blood administration set with a 200 micron filter MUST be used when transfusing plasma. It must be remembered that any heat above body temperature has the ability to activate the fibrinogen in the plasma, converting it into fibrin – in other words, the whole bag turns into a CLOT! The remaining plasma is still safe to transfuse, however the filter in the blood administration set will clog from blocking the fibrin particles, and may need to be replaced repeatedly. Some fine flakes may be visible as the bag thaws. These “flakes” are cryoprecipitates and should disappear as the plasma warms, but it is not unusual if some flakes are still visible at the time of transfusion – their presence is completely normal, and the reason why a blood administration set with a 200-micron filter must be used.


Plasma must be kept frozen until placed in water bath.

  1. Working over a bench, preferably covered with some sort of cushion (a doubled towel), tip the bag of plasma out of the box, into your hand.
  2. Fill a sink or water bath with water NO WARMER than 40⁰ Centigrade (35⁰ C is ideal).
  3. Ensure that the hot water is evenly mixed with the cold water.
  4. A thermometer MUST be used.
  5. Please do not use heating elements.
  6. Place the bag into the water – have enough water in the sink so that the bag FLOATS.
  7. The thermometer must be in the water bath for the duration of the thawing process.
  8. Further hot water will need to be added during the thawing process to ensure that the plasma is approximately at body temperature for transfusion. The bag of plasma should be removed from the water bath while the extra hot water is added. The plasma cannot come into contact with the hot water (greater than 40⁰ Centigrade) as it is running from the tap.
  9. If you are heating the plasma after thawing it in a fridge, the same rule applies. The water is to be no warmer than 40⁰C, and a thermometer must be used.
  10. If thawing is performed by lay staff, please review their procedures from time to time – e.g. the start of foaling season.