Posted by Wendy Wise on
Thawing Plasma for Research
Normal plasma contains a multitude of coagulation proteins for hemostasis which is the stopping of blood flow after injury. While the addition of anticoagulants such as citrate and EDTA will limit the activation of the coagulation cascade leading to undesired clotting, hemostasis can still be triggered by a range of factors. A common mistake that causes unwanted clotting is incorrect thawing and freezing methods. A key consideration in the handling of plasma is the avoidance of slow freezing or thawing which can lead to precipitation and inadvertent coagulation. Innovative Research is providing the following protocols to ensure our customers can preserve the quality of the precious plasma samples they have purchased.
- Preheat a water bath to 37 C.
- Place the frozen plasma sample directly in the water bath.
- Gently agitate the plasma sample every 5-10 minutes to insure even thawing.
- The total thawing time will depend on the frozen sample volume. A 10 ml sample might be thawed completely in 5 minutes, but a large sample could take up to 1 hour.
- The thawed sample should be used immediately or stored at 4 C for up to 24 hours. Liquid plasma should never be kept on ice or stored below 0 C as the cold may cause clotting.
- Plasma should be visually inspected for signs of clotting or precipitation before use in experiments. A coagulation test such as aPTT can also be performed to verify the preservation of the hemostasis system.
- Plasma should always be snap-frozen by placing the tube in dry ice for at least 1 hour. Large containers can be covered in dry ice for even freezing.
- Frozen plasma should be stored at –20 C or colder. Lower temperatures will help preserve labile plasma proteins for longer time periods.
This protocol is applicable for plasma containing any anticoagulant of both human and animal origin. While handling serum does not involve the same risk of clotting due to improper handling, we recommend following the above instructions for both plasma and serum for best results. Many abundant plasma proteins such as albumin, immunoglobulins, and fibrinogen are stable for multiple freeze-thaw cycles and liquid storage. However, labile components including Factor VIII and the complement system will be rapidly degraded during liquid storage and freeze-thaw cycles. All human blood products we provide should be handled at Biosafety Level 2 to prevent possible transmission of potentially infectious agents.
Products related to this topic:
Pooled Human Plasma (Blood Derived)
Single Donor Human Plasma (Blood Derived)