Stem Cells|FAQs

Frequently Asked Questions

View the frequently asked questions in cord blood banking and stem cell collection. Also read more information on Smart Cells and how we operate here, or visit our about Smart Cells page.


Smart Cells has an HTA licence which covers procurement, testing, processing, storage, import, release, and export of cord blood cells and tissue. Smart Cells has ISO9001:2015 certification, and participates in the UK National External Quality Assessment Service (NEQAS) quality assurance scheme for full blood and CD34 cell counting.

Smart Cells takes ongoing Quality Assurance very seriously, with a rigorous programme of validating and auditing all critical practices and procedures. Fully trained and experienced staff operate according to validated procedures. The Smart Cells laboratory technical team are educated to degree and post graduate degree level in relevant biomedical sciences and use globally recognised techniques and technologies in the state-of-the-art processing facility.

The Smart Cells approach to ongoing Quality Assurance, regulatory compliance, integrity, and transparency is supported and overseen by the Scientific Director, Head of Laboratory Operations, and Quality Officer.

With 28 years of experience in stem cell transplantation in the NHS, and considerable academic and research experience, Smart Cells’ Scientific Director Dr. Ann Smith ensures Smart Cells meets best practice in the field. Her expertise is available to parents, partners, and healthcare professionals directly or via the customer services team.



Cord blood transplantation is a clinically effective form of treatment for many patients with cancer and blood diseases who need a stem cell transplant.  In the last decade, cord blood has become a relevant source of cells in regenerative medicine.

While there is no definitive consensus on exactly how long frozen cord blood can be stored scientists and clinicians worldwide are of the opinion that if cryopreserved and stored properly, then storage can be for decades or more.  Smart Cells use state of the art processing, cryopreservation, and 24/7 monitored storage technologies designed to optimise the viability of stem cells. In vapour phase nitrogen temperatures below -170 degrees Celsius, all metabolic activities in cells are suspended, meaning there should be no deterioration. The majority of public and private banks worldwide use similar tried and tested technologies.

Key work undertaken by Professor Hal Broxmeyer, a distinguished world leader in the field of cord blood therapeutics has demonstrated efficient cell recovery after storage times of 5, 10, 15, 23.5 and most recently  27 years after cells were cryopreserved (1, 2, 3).

Cord blood storage has been available for  just over 3 decades, although in the early years not many units were being stored and used.  It is therefore not possible to look at empirical data beyond that time point, however Professor Broxmeyer’s team have confirmed that long-term cryopreservation for at least 27 years does not significantly alter the numbers and function of the critical haematopoietic (blood making) stem cells found in cord blood.

Realistically, it is in the last 20 years approximately that transplantation using cord blood has become a fully accepted therapeutic option and experts in the field have confidence that ongoing cord blood banking and use should continue as there are well worked out therapeutic strategies in place in addition to refinements and innovations being developed (4, 5, 6).

The Anthony Nolan Cord Blood Bank FAQs states:  “How long will you store my baby’s cord blood?

We’ll store it until someone needs it for a transplant (or for research if there aren’t enough stem cells to use for a transplant). We can store indefinitely, frozen in cryogenic tanks at temperatures of around -190oC” (7).


At Smart Cells, six years is the longest interval between storage and thawing of frozen cord blood cells that were given to a patient as a transplant which was satisfactory in terms of cell recovery and engraftment. No units older than this have yet been requested.

As part of Smart Cells’ Quality Assurance programme and regulatory compliance, the team regularly undertake validation studies to ensure that the processing, freezing, and storage of cord blood is efficient and that total nucleated and viable CD34+ stem cell recoveries are satisfactory after thawing.Provided procedures to process, store, and thaw stem cells are of a high standard, the main factor that can potentially affect the ultimate post-thaw recovery is the original quality of the cord blood sample itself. Those with initial low viability may not withstand the thawing process in the same way as a more robust product.

The tested timeframe will likely change and be extended as time goes on and clinical studies demonstrate conclusively that cord blood stem cells are viable after long-term frozen storage beyond 30 or more years. Clinical proof will require treating of patients with cord blood units that have been in storage for decades but for now, Smart Cells’ advice aligns with current worldwide expert opinion.







7) cord/umbilical-cord-faqs


Review the Public Health Guidelines on Zika Virus here: Public Health Guidelines

Advice for mothers wishing to store cord blood at risk of Zika Virus:

Obligatory must not donate if:

  1. a) A mother has been diagnosed with chikungunya, dengue or Zika Virus infection whilst in an endemic area or following her return to the UK during this pregnancy. OR PARTICULAR PARTNER COUNTRY
  2. b) A mother has either had a history of symptoms suggestive of chikungunya dengue or Zika Virus infection whilst in an endemic area or following her return to the UK during this pregnancy. OR PARTICULAR PARTNER COUNTRY
  3. c) In other cases it is less than four weeks from a mother’s return from a Tropical Virus Risk endemic area.

Source: UK National Blood Service

Smart Cells recommend that you speak to your GP if you have any concerns regarding Zika Virus.


Collection must be performed by a trained and licensed healthcare professional. This could be a private obstetrician or midwife or an assigned phlebotomist.

The Human Tissue Authority (HTA) requires the person who performs the collection to be appropriately trained in the Smart Cells collection process and hold a valid Third-Party Agreement to do so. Smart Cells can arrange for a fully trained and qualified medical professional to carry out the collection at your birth.

TNC stands for Total Nucleated Cells which are the white blood cells within a cord blood sample. Smart Cells count these cells as this is an important measurement of the success of the collection in terms of cell numbers. Within the TNC cell fraction, the Smart Cells team look at numbers of CD34 positive cells. This is a critical measurement as CD34 is a marker of stem cells.  Both TNC and CD34 levels in a cord blood sample are taken into account by clinical teams when deciding if there are sufficient stem cells for treatment.

The median size of cord blood collections in family banks is 60mL or two ounces. The number of Total Nucleated Cells (TNCs) and CD34 positive stem cells can vary from cord to cord regardless of volume but generally larger volumes contain more TNCs and CD34 positive cells.  Smart Cells will always inform you about the volume of your sample and the cell counts.

Yes, Smart Cells has a fully trained team of phlebotomists* who are able to visit your home to collect the sample during a home birth. They will discuss your options with you and make sure they have a safe and sterile area to collect your samples.

*Specific to the United Kingdom only.

You can either wait for the placenta to deliver naturally or the delivery may be induced via an injection. Either method does not prevent Smart Cells from collecting your sample.

Smart Cells offer all customers the opportunity to spread the final balance on a payment plan. Customers can spread costs over 3, 6 or 12 months and there are no additional fees to do this.

 “HLA” is short for Human Leukocyte Antigens, which are proteins in the immune system that determine whether a patient will react against a donor transplant or if the donor transplant cells will react against the recipient. A very good basic tutorial about HLA types is on the Stanford Website, and the national Be The Match program (aka NMDP) has more info on the role of HLA type in transplants of stem cells from bone marrow or cord blood.

The HLA type of cord blood is always assessed by public banks at the time of storing cells, and then the type is listed on a registry that can be searched  for patients worldwide who need  a transplant. Family/private banks typically do not measure the HLA type at the time of banking, as the actual test specification varies depending on the proposed clinical use and the testing can always be checked later using a testing segment of the stored cells.

In the case of sibling transplantation, individuals have 25 per cent chance of having a sibling who is HLA matched.

All the reasons you banked for the first child are still valid for additional children.

  1. If you want your baby to have the option of using his/her own cells, then you need to bank them.
  2. If you are banking to cover siblings, then the ability to use cord blood from one child for another depends on whether they have matching HLA types. Two full siblings have a 25 per cent chance of being a perfect match, a 50 per cent chance of being a half match, and a 25 per cent chance of not matching at all. For a cord blood transplant, donor and patient must match at least 4 out of 6 HLA types. The more siblings with banked cord blood, the more chance that they cover each other for possible transplants or other therapies for which sibling stem cells are accepted.

References: Odds of sibling match are based on haplotype inheritance: that the child will receive 3 HLA types as a group from each parent.

Source: Parent’s Guide to Cord Blood

No. After cord blood and/or tissue is collected at birth, the samples are delivered, processed, and stored in the Smart Cells UK laboratory. If you ever need the cord blood or tissue for therapy, the product will be shipped in a constant temperature monitored frozen state in a special container designed for the purpose of international cell shipment. Cord blood can travel anywhere in the world with no loss of viability because it travels frozen. It is only thawed at the clinic where it will be used immediately prior to infusion. Smart Cells have successfully shipped samples within the UK and to Europe, USA, India, and the Far East.

Most UK and international cord blood banks, both public and private, process cord blood to reduce levels of the plasma and the red cells, and cryo-preserve the remaining buffy coat portion which contains mononuclear cells. This mononuclear cell fraction contains the critical CD34 positive stem cells. It is valid for cord blood storage banks to use volume reduction techniques as such units are clinically preferable to whole blood, red cell replete products. This is based on large cohorts of international data from respected and accredited transplant centres who use cord blood regularly as a therapeutic tool. The plasma and red cells in cord blood are not deemed to be useful clinically. By reducing the volume of the sample, while retaining the critical stem cells, it is possible to minimise the volume of cryoprotectant solution required in the freezing process. The cryoprotectant contains a substance called DMSO that can cause reactions in patients so it is sensible to reduce the volume as much as possible.

The reduction of red blood cell content is very important as it is well recognised that red blood cells burst or lyse during the freezing process. This results in release of free haemoglobin and red cell debris which can cause complications to patients at the time of infusion.

There are whole cord blood units in-store that was mostly banked before preference for volume reduction became a factor and some of these are used for transplantation if there is no better match available in the volume-reduced format. Under these circumstances, key worldwide organisations which issue standards of practice recommend washing the units to remove lysed red blood cell material to avoid clinical complications. However, this can result in the loss of some stem cells.

Information taken from the following sources:

The Joint Accreditation Committee-ISCT (Europe) & EBMT (JACIE) : The Hematopoietic Cellular Therapy Accreditation Manual 6th Edition which accompanies the FACT-JACIE International Standards for Hematopoietic Cellular Therapy Product Collection, Processing, and Administration.

The National Marrow Donor Program® (NMDP), ( USA)

Transfusion. 2012 Jan; 52(1): 207–208

The Circular of Information for the use of cellular therapy products (AABB publication)
Ballen et al. Biol Blood Marrow Transplant. 2015 Apr; 21(4): 688–695.!po=0.617284

Smart Cells offer a fully private storage option for the long-term storage of cord blood and tissue. This service is a paid service and the samples are solely stored for your own private use. If you wish to enquire more about cord blood and tissue donation then please visit the NHS Blood Bank or the Anthony Nolan Trust:


Stem cells may be used in mainstream transplantation to help treat blood and bone marrow cancers or diseases such as Thalassaemia or sickle cell disease. If the cells being used are autologouse (from the individual for their own use), they are able to restore the blood and immune systems following chemotherapy used to treat the disease. If the transplant is allogeneic (from one sibling to another), not only can the cells restore the blood and immune systems, but they may play a role in cancer destruction too.

Stem cells may also be used in regenerative medicine to help repair or replace damaged or diseased tissues or cells.  These evolving regenerative applications are fairly recent and are typically being undertaken as part of research or clinical trials. View more information on the rest of the Smart Cells website.


The majority of maternity hospitals allow Smart Cells to perform this service for you. If you would like to discuss your individual hospital, then please contact the Smart Cells team.




Delayed cord clamping is a birth practice in which the umbilical cord is not clamped or cut until after pulsations have ceased, or until after a given period of time has elapsed. According to the World Health Organization, delayed clamping refers to the cord being cut 1-3 minutes after birth – a practice they recommend for all births.

Delayed cord clamping provides benefits to your baby, including a normal healthy blood volume, good oxygenation and heart rate for the transition to life outside of the womb. Additionally, a higher haemoglobin level with improved iron stores in early life could potentially have a favourable effect on development outcomes, in infants for the first few months post-birth.

Yes, it is possible to delay cord clamping and also collect cord blood provided there is sufficient blood remaining in the umbilical cord while also allowing some of the blood to flow to the baby. The World Health Organisation guidelines indicate a delay of 1-3 minutes can benefit the baby, however choosing to delay and for how long is a matter for you to decide in dialogue with your healthcare professionals.

Read more about delayed cord clamping & umbilical cord blood banking here.


Parents Guide To Cord Blood Foundation

WHO Data Guideline: delayed umbilical cord clamping for improved maternal and infant health and nutrition outcomes.

RCOG Clamping Of Umbilical Cord and Placental Transfusion – Scientific Impact Paper (No 14),not%20require%20positive%20pressure%20ventilation:

No. If you have a Caesarean the collection can take place after the delivery of the placenta, as it would with a natural birth. Either birthing scenario is fine for the collection of cord blood and cord tissue stem cells.

No. Cord blood and tissue collection is painless, convenient, and safe for both mother and new-born. The cord blood and tissue samples are collected after your baby is born and the umbilical cord has been clamped and cut. The samples collected are normally discarded after birth as medical waste.


No additional costs will be incurred for the transportation of the sample at any time for therapeutic use.

If an HLA test is required, the cost of a low-resolution test is covered. If clinical teams require high-resolution testing, there may be an extra cost.


Establishments licensed by the HTA are legally required to ensure that in the event of activities ceasing, any tissues/cells and records are transferred to another suitably-licensed establishment. Smart Cells is compliant with this requirement.


Smart Cells was founded in 2000 and has been collecting samples ever since.

Yes, if you refer a friend, and if they bank with us, both you and your friend will receive a £50 Amazon voucher. There is no limit on how many referrals you can make. T&Cs apply.
Refer a friend NOW!!




Ready to get started or need more information?

Claim your free guide online or talk to us to find out more

Where did you hear about us?
DD slash MM slash YYYY
By clicking submit (below) you are requesting a Free Smart Cells Guide and agreeing to your information being processed as outlined in our Privacy Policy. Your data will not be shared with any Third Parties.
This field is for validation purposes and should be left unchanged.


Claim your free guide