TME 66: How Do We Store Blood & For How Long?

Blood transfusions save millions of lives every year, but have you ever wondered how donated blood is stored and preserved? From battlefield innovations to cutting-edge cryopreservation, the science of blood banking has undergone remarkable advancements.

Image courtesy: AI

Blood Storage Duration: Key Facts

The shelf life of donated blood depends primarily on two factors:

1. The type of blood component

2. The preservative or additive solution used

   
   

Here's the current storage landscape:

Component	Storage Temp	Shelf Life	Key Preservative
Whole Blood	2–6°C	21–35 days	CPDA-1
Red Blood Cells	2–6°C	35–42 days	SAGM/AS solutions
Platelets	20–24°C	5–7 days	Agitated storage
Fresh Frozen Plasma	-18°C or below	1 year	Frozen immediately
Cryoprecipitate	-18°C or below	1 year	Frozen storage

How Wars Forced Blood Banking Innovations

Military conflicts have been unexpected catalysts for blood storage advancements. The simple equation: war → wounded soldiers → massive blood demand → innovation.

Key wartime breakthroughs include:

• WWI (1914-1918): Discovery of sodium citrate as an anticoagulant

• WWII (1939-1945):

  • Development of CPD (Citrate-Phosphate-Dextrose) solution

  • First mobile blood banks

  • Transition from glass to plastic blood bags

• Korean/Vietnam Wars:

  • CPDA-1 extended storage to 35 days

  • Improved battlefield transfusion protocols

These military-driven innovations later benefited civilian medicine, creating today's robust blood banking systems.

Image courtesy: AI

Inside the Blood Bag: Anticoagulants and Additives

Modern blood preservation relies on sophisticated chemical cocktails:

Anticoagulants

1. CPD (Citrate-Phosphate-Dextrose)

   • Citrate chelates calcium to prevent clotting

   • Phosphate buffers pH

   • Dextrose nourishes RBCs

2. CPDA-1

   • Adds adenine to support RBC energy needs

   • Extends storage to 35 days

   
   

Additive Solutions (SAGM)

The current gold standard for RBC storage:

Component	Function
Saline	Maintains osmotic balance
Adenine	Supports ATP production
Glucose	Cellular energy source
Mannitol	Prevents hemolysis

These additives work synergistically to maintain RBC viability for 42 days - nearly twice as long as early storage methods.

Pushing the Limits: Cryopreservation and Beyond

For long-term storage, scientists have developed cryopreservation techniques:

• Method: RBCs frozen at -80°C with glycerol

• Shelf Life: 10+ years

• Process:

  1. Glycerol added as cryoprotectant

  2. Slow freezing to -80°C

  3. Thawing and deglycerolization before use

While revolutionary for rare blood types and strategic reserves, the complex thawing process limits emergency use.

The Cutting Edge: Recent Advances

Blood banking continues evolving with these breakthroughs:

1. Pathogen Reduction Technology

   • Uses UV light/chemicals to neutralize pathogens

   • Enhances safety for platelets and plasma

2. Cold-Stored Platelets

   • Refrigeration may extend shelf life

   • Reduces bacterial contamination risk

3. Artificial Blood Substitutes

   • Hemoglobin-based oxygen carriers (HBOCs)

   • Perfluorocarbon emulsions

   • Still in clinical trials but promising

4. Dried Plasma

   • Lightweight, room-temperature stable

   • Ideal for military and disaster response

5. Next-Gen Additives

   • Experimental solutions like PAG3M

   • May extend RBC storage beyond 42 days

   
   

   

   Image courtesy: AI

   
   

The Future of Blood Banking

As we look ahead, several trends are emerging:

• Personalized blood products matched to patient needs

• Stem-cell derived blood for unlimited supply

• Nanotechnology for improved oxygen carriers

• Automated blood processing for greater efficiency

Did you know? A single blood donation can save up to three lives. Consider donating at your local blood center.