Blood Sample Transport and Storage
Blood samples require specific temperature regulation as they undergo both processing and storage. A large part of their usefulness depends on proper procedures. One of the largest issues occurs during transportation, and entire shipments of specimens can be destroyed without proper handling. With blood (and blood components) more in demand than ever, it’s crucial that these specimens go through the cold chain and reach their final destination without losing integrity.
|Condition||Acceptable Temperatures||Viability Time|
|Pre-processing||20-24C (68-75F)||6 hours or less|
|Storage (pre and post processing)||2-6C (35-43F)||35 days (estimated)|
|Processed, transporting||2-10C (35-50F)||24 hours or less|
The guidelines for transporting blood components vary based on the component in question (plasma, red cells, white cells, platelets). However, these are generally accepted storage conditions within the viability time (or time in storage), endorsed by the NBTC (National Blood Transfusion Council).
Blood in the Cold Chain
Proper handling of human biospecimens, and in particular blood, is crucial to preserving their integrity. It’s not even the ultimate condition the repository receives them in that determines their viability. Many blood samples and stocks go through cold chain transport to reach their final destination. Essentially, the cold chain is a term used to describe the process of shipping products that require freezing or refrigeration through both their transport and storage at the destination.
Cold chain transport can include refrigerated trucks, containers within planes (air transport), cold cars in trains, and even shipping by sea (boats and freighters). No matter the method, the important aspect is that the goods remain cold, and at acceptable temperatures to preserve their integrity.
The blood and medical cold chain involves everything from storage and transport, to the equipment and workers involved.
The Components of Blood
There are various different components of blood that go through the cold chain to reach their final destination. Most people are familiar with whole blood, which is essentially blood drawn from the veins. However, there are other components of blood that are just as essential to the medical industry.
The most crucial components of blood include:
Whole blood – Blood taken in whole form, without any separation
White blood cells – Also known as granulocytes. These are components of blood that help the body fight off infections. These are much less common, because of their short term use and the possibility of ill side effects.
Red blood cells – Often abbreviated as RBC. These are the blood cells that help the body transport oxygen. Red blood cell transfusions are far more common, especially in patients with a low blood count.
Plasma – This is part of the blood, and when separated from other components, it has a somewhat transparent, yellow color. Plasma supports blood cells, although plasma transfusions are more common for people with poor blood clotting.
Platelets – These help with blood clotting, and while they are fairly common for transfusions, they have a short viability time. Platelets often last for only between 8 and 10 days.
For more information about the components of blood, and types of transfusions, see the AAMDS Foundation website.
Keep in mind that no matter what type of component goes through shipping, a constant temperature is crucial. Fluctuating temperatures can have serious consequences on the quality and viability of any blood component.
The Neo Sensor measures all temperature ranges for storing blood components and beyond (-40℃ to 70℃).
How to Transport Blood in the Cold Chain
Transporting blood, like any medical product, is no simple process. From the collection site to the packaging, all the way to the final destination, every step is important. Transporting whole blood is one thing, while transporting the different components of blood is another thing entirely.
These are guidelines for how to properly transport each blood component, and the temperatures they need to stay at:
Whole blood is perhaps the easiest to ship, because it doesn’t require extensive refrigeration. However, it does need a quick transport process. Before processing whole blood it can undergo transportation at between 68 and 75 degrees fahrenheit (20-24 celsius). This temperature range is safe, but only for up to six hours.
After six hours, whole blood must be stored at much cooler temperatures. For extended storage and transportation, whole blood should stay between 35 and 43 degrees fahrenheit (2-6 celsius). This rule applies whether the whole blood is in the pre or post processing stage. Once between 35-43 degrees, whole blood is viable for approximately 35 days.
White blood cells
While white blood cells aren’t as common as other types of blood transfusion, they still require strict shipping and storage temperatures. Once white blood cells undergo processing (and are considered stable), they have even greater temperature tolerance than whole blood, for a limited period of time. WBCs (white blood cells) can stay at temperatures up to 86 degrees fahrenheit (30 celsius) for up to five days.
After the five day mark, white blood cells need more extensive temperature control. They should then be in a freezer, or temperature controlled shipping unit, at -4 degrees fahrenheit (-20 celsius).
Red blood cells
The way we store red blood cells (RBCs) is undergoing a change from the past regulations. In previous decades, a temperature range of 33.8 to 42.8 degrees fahrenheit (or 1 to 6 celsius), was acceptable for long term storage. While that is still common practice in many medical fields, many organizations are beginning to change their recommendations for RBC storage.
Now, many organizations recommend storing red blood cells between 35.6 and 39.2 degrees fahrenheit (2 to 4 celsius). Storing them at extremely low temperatures (and freezing them) essentially destroys the cells. Higher temperatures greatly decrease their ‘shelf life.’ Keeping RBCs within the proper temperature range not only slows potential microbial growth, but also limits the cell metabolism (glycolysis).
Plasma has very strict storage and transport temperature requirements. This is one of the reasons plasma is frozen once separated from the whole blood. While plasma can stay in ambient temperatures for up to 24 hours, most medical organizations recommend no more than 6 hours without freezing.
Once frozen, plasma should be kept between -4 and -16.6 degrees fahrenheit (-20 to -27 celsius). However, before that, plasma needs to undergo a fast freezing process that brings it below -22 degrees fahrenheit (-30 celsius) to preserve it.
While in transport, the plasma must stay cold, although a temperature excursion up to 5 degrees fahrenheit (-15 celsius), is acceptable. However, this is only if the temperature excursion lasts less than 72 hours (consecutively), and does not occur more than once during transport.
Platelets have different temperature requirements depending on whether they’re in transport or storage. Not only that, platelet temperature storage also depends on whether continuous and gentle agitation is possible.
While in transport, platelets are safely within temperature requirements when they’re between 33.8 and 50 degrees fahrenheit (or 1 to 10 celsius). However, once they arrive, they need to be stored between 33.8 and 42.8 degrees fahrenheit (1-6 celsius). This is assuming the constant agitation isn’t feasible.
When continuous agitation is possible, platelets are in a safe temperature range between 68 and 75 degrees fahrenheit (20 to 24 celsius). However, because a safe, constant method of agitation isn’t always possible or cost effective, many companies choose to cool platelets instead.
Blood Quality Problems From the Cold Chain
There are many issues concerning blood quality when samples go through the cold chain. Of course, the cold chain is the major method of making sure blood arrives at the repositories, labs, hospitals, and other centers that need it.
Standard regulations require reading the temperature both before shipping and after arrival. Unfortunately, this does not ensure a high quality specimen. Refrigerated shipping containers can bring temperatures low enough to ensure a proper reading upon arrival. However, the specimens might still undergo a temperature excursion that goes undetected.
For instance, if a truck’s shipping container is opened during the trip, the specimens can reach unacceptable temperatures. However, if the container is closed back up, and has time to cool back down to proper temperatures, the recipient might never know the specimens were compromised.
Even if blood specimens arrive at the proper temperature, a temperature excursion affects their quality, and their viability.
The biggest risks when blood goes through the cold chain include:
This is a large risk, in particular for whole blood and red blood cells. Red blood cells carry oxygen from the lungs to the rest of the body. Once these specimens are collected, they’re only viable (without refrigeration) for a short time. After that time, they begin losing their ability to carry oxygen. A temperature excursion, whether during shipping or storage, can ultimately negate one of the biggest reasons for using it for a transfusion.
Any time blood specimens fall outside of proper temperatures shortens their time before expiration. The longer blood components are in temperature excursions, the less time they can be used for. In certain instances, like with plasma, blood components can tolerate temperature excursions for a limited time. However, that is only if the specimens still stay within a certain temperature range (i.e. plasma can be at -15 celsius, rather than the advised minimum of -20C, but only for up to 72 hours, and it can only happen once).
With any temperature sensitive product, bacteria and other microbes can develop in the right conditions. Even refrigerated products are at risk for some microbial growth. While refrigeration won’t kill microbes, it will delay or halt their growth. Freezing may kill some germs and bacteria, although in most cases it doesn’t. In fact, it typically puts them into a sort of stasis which actually preserves them.