What Is a Leukopak?

A leukopak (short for "leukocyte pack") is a concentrated collection of white blood cells — the immune cells that fight disease. While a standard blood draw collects a small tube of mixed blood, a leukopak uses a machine called an apheresis device to separate and collect just the white blood cells, then return everything else to your body.

Think of it like panning for gold: the machine sifts through your blood, keeps the white blood cells researchers need, and gives you back the rest.

White blood cells are the foundation of immunology research. They can't be synthesized in a lab — they must come from real donors. A single leukopak contains billions of immune cells — enough for multiple experiments.

Researchers use leukopak specimens for:

• CAR-T cell therapy development — engineering immune cells to fight cancer
• Cancer immunotherapy trials — testing new treatments that activate the immune system
• Autoimmune disease research — understanding why the immune system attacks itself
• HIV vaccine development — studying immune response to viral infection
• Organ transplant research — preventing rejection and improving outcomes

Because of this demand — and because the process takes longer than a standard draw — leukopak donors earn $400–$650 per donation. Donors with specific health conditions are especially valuable, as their white blood cells carry the exact disease markers researchers need to study.

Donors with conditions like autoimmune disease, HIV, or cancer often have elevated white blood cell counts — making them ideal leukopak candidates. Your condition isn't a barrier. It's often the reason researchers want your specimen most.

The right choice depends on your schedule and comfort level. Standard draws are fast and simple — ideal if you want to donate frequently. Leukopaks are a bigger time commitment but pay significantly more per visit. Many donors start with standard draws and move to leukopaks once they're comfortable with the process.