The Process of Cord Blood Preservation

Most of us have some passing familiarity with the process of donating blood. You donate blood, the blood is tested to make sure it doesn’t carry any infections or diseases, it’s processed and stored and then hopefully, it finds its way to someone who needs it before its expiration date. Blood is either preserved whole or separated into its component parts. Refrigerated whole blood can last only a few days, while donated platelets can last five days and donated red blood cells can last about 42 days. If the plasma is separated out and frozen, it can be preserved and stored for about one year.

The process for preserving cord blood is similar in many respects. Cord blood is obtained when a baby is born, after the umbilical cord is clamped. It may be collected in a syringe or in a blood bag, and the collection process is usually carried out by the obstetrician after the delivery and post-delivery care are completed. The obstetrician will usually collect as large a sample as possible, and although the minimum size for a sample is around 75 milliliters, most samples average around 100 milliliters. If you’re having your blood stored at a private facility, it may provide you with its preferred collection materials for your doctor to use.

Once the umbilical cord blood has been collected, it must be delivered to the preservation facility as quickly as possible – ideally within 24 hours. This may be done by courier or by special delivery, such as overnight delivery. The umbilical cord blood should remain at room temperature – it shouldn’t be refrigerated or frozen, and it shouldn’t be allowed to become overheated by being left in a car or subjected to other warm conditions.

Once the blood sample reaches the lab, a small amount of the blood is removed for testing. The blood will be tested for bacteria and to make sure the sample hasn’t been contaminated in some way. The blood will be tested for blood borne diseases such as Hepatitis and HIV, and an HLA profile will be developed which is necessary to match the blood with a potential recipient in the future.

After testing, a chemical preservative known as a cryopreservant will be added to the blood. This will help prevent the cells from being damaged during the freezing and thawing process. When liquids are frozen, ice crystals form that have jagged, sharp edges that can literally tear holes in the cell walls. To preserve the cells, the cryopreservative helps to minimize the formation of ice crystals, thereby limiting potential damage to the cells. The sample will be slowly cooled, then frozen in liquid nitrogen. The average temperature for cell preservation in liquid nitrogen is roughly negative 196 degrees Centigrade.

The particular procedures and preservation methodologies vary from blood bank to blood bank. One private bank, for example, splits the samples it receives into two separate samples and stores them at different locations. In the event that one storage facility is damaged or its samples are somehow compromised, then another sample remains.

If you’re interested in preserving your child's cord blood, the blood bank you’re considering should be able to answer all your questions about its policies and procedures.