How Are Stem Cells Preserved?


Is it not surprising to see newborn babies coming to this world with potential lifesavers in the form of stem cells packed in their umbilical cord? With advancement in science and technology, it is possible to freeze and preserve these precious cells for decades without losing its healing ability through cord blood banking. It is the process of preserving the stem cells in the umbilical cord under cryogenic conditions for decades so that they can be retrieved and used when required for therapeutic reasons. There is a growing awareness among public about the importance of stem cell banking and parents are aware of the processes involved in collection and preservation of stem cells. However, they do not have access to see what is happening to these stem cells inside the lab. Here is a special preview on the preservation process of umbilical cord samples inside the stem cell labs: Processing Of Umbilical Cord Samples When the samples arrive at the lab, they are taken for testing. Usually, the maternal blood sample is tested to ensure that the sample is free from contamination of infectious diseases. The cord blood and cord tissue samples are also tested for cell count and viability (to check if the cells are active and suitable for preservation) before initiating stem cell processing. Cord Blood Sample Processing

After testing, the samples are moved to the processing area. The processing area and the equipments must be completely sterilized to avoid external contamination during the extraction of stem cells. The umbilical cord blood contains not just stem cells but also other components of the blood which needs to be removed before preservation. The umbilical cord blood undergoes centrifugation and other techniques to separate red blood corpuscles (RBCs) from stem cells. A good stem cell extraction technique depends on 2 criteria:

  1. High stem cell recovery – The volume of stem cells recovered from the sample which can be estimated by cell count technique.
  2. Reduction of RBCs

Once the stem cells are extracted from the sample, they undergo various quality tests to ensure the sterility and viability of the stem cells.

Cord Tissue Sample Processing

The processing of cord tissue is extensive and requires a different protocol to extract the mesenchymal stem cells. An aseptic sterile laboratory environment is maintained as the cord tissue is sticky in nature and prone to contamination. The sample is moved to the cold room where it is cut into small pieces and cultured using explant culture technique to increase the number of stem cells. The culture is kept in an incubator for the cells to proliferate and the growth is carefully monitored. After a certain period, the stem cells are extracted at cell harvest and checked for growth and cell count.

Preservation of Stem Cells

If the extracted stem cells are viable, free of contamination and shows desired amount of cell growth, they are placed in cryo vials and moved to the cryopreservation area. The cryo vials are kept inside aluminium canisters and left within the controlled rate freezer; this will slowly bring down the temperature to -198 degree Celsius. The canisters are then placed in the cryopreservation cylinders that are filled with liquid nitrogen to maintain the freezing temperature.

The stem cells are carefully stored in the cryopreservation room for long term storage. On successful preservation, the stem cell bank will provide a preservation certificate to the parents which will include the details about the samples such as cell count, preservation date etc. Once you receive the preservation certificate, you will know that your little one’s precious stem cells are lying safely inside the lab and they will remain healthy for a lifetime.


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