Many parents choose these days the blood of your baby's umbilical cord frozen and stored as a future source of stem cells. This article examines the various ways in which stem cells and stored blood samples. The process of having your baby's umbilical cord blood, processed in a laboratory and kept in frozen storage is relatively new. The idea is that all blood stem cells or stem cells themselves are available for future use, if a child of any medical treatment they need. While some treatments, such as sickle cell anemia, leukemia and Hodgkin's disease through all these cells, the idea is also a pool of compatible cells that can be used in treatments are being developed. Since the use of such cells for medical treatment is the subject of current research, therefore, the likelihood of new treatments are available in the future is high. These future therapies have the potential to cure diseases, injuries and able to offer today incurable. The collection and storage process begins right after birth, when the kit of umbilical cord blood collection provided by the storage company used by one of the medical professionals to safely and painlessly collects cord blood cord. This sample was transported to the laboratory for processing the storage company. Some companies make stem cells from cord blood freezing of the sample, while others freeze the blood. Phase liquid nitrogen freezes the sample in a storage tank of liquid nitrogen cooled around minus 190 degrees Celsius. The low temperature can preserve the quality of the sample for many years. However, the main factors of storage tank design to take into account when deciding which method of choice for storage. The two main types of tanks both use liquid nitrogen to freeze, but use it in different ways. The oldest method uses liquid nitrogen in liquid phase to the sample to freeze and maintain the temperature required for storage. The important thing to remember is that most of the samples of other people in the same VAT. The nature of the liquid phase of nitrogen in the tank means that there is a potential risk of contamination of samples of infectious particles if one or more infected samples in the tank. Liquid nitrogen can drag infectious particles such as viruses, among the samples. There is evidence that transmission of hepatitis B virus has occurred between samples, while samples were stored in nitrogen vapor phase liquid nitrogen .* The other storage designs also used liquid nitrogen, but uses differently. Liquid nitrogen is confined to the walls of the storage container, and only nitrogen vapor in contact with the samples. This means that the infectious particles present in a sample can not be transferred to other samples in order to cause infection. In the past expressed concern about the ability of the nitrogen vapor to maintain the proper storage temperature when the tank is opened for access. Improvements in the design now means that a constant temperature can be maintained in storage tank design. R. Tedder *, M. Zuckerman, A. Goldstone, A. Hawkins, A. Fielding, E. Briggs, D. Irwin, S. Blair, A. Gorman, K. Patterson, D. Lynch, J. Heptonstall, and N. Brink. 1995. Hepatitis B transmission from contaminated cryopreservation tank. Lancet 346: 137-140.