Method and system for collecting leukoreduced red blood cells

1. A method for collecting leukoreduced red blood cells employing a spinning membrane separator including a membrane configured to spin about a generally vertically-oriented axis within a housing, the housing including an upper end region and a lower end region in an operating position and the separator including a red blood cell outlet in the upper end region of the housing and a whole blood inlet in the lower end region of the housing, the method comprising:

flowing additive solution from a first container into the whole blood inlet of the housing to prime the separator;

flowing whole blood into the whole blood inlet of the housing;

separating red blood cells from the whole blood;

flowing separated red blood cells out of the red blood cell outlet of the housing through a red blood cell flow path;

combining the separated red blood cells with additive solution from the first container in the red blood cell flow path;

passing the separated red blood cells and additive solution combination directly from the red blood cell flow path through a leukoreduction filter; and

collecting the filtered red blood cells and additive solution in a second container.

2. The method of claim 1 wherein the additive solution comprises a low-viscosity non-biological fluid.

3. The method of claim 1 wherein the additive solution comprises a preservative solution.

4. The method of claim 1 wherein flowing additive solution into the whole blood inlet comprises pumping additive solution into the inlet.

5. The method of claim 1 wherein combining red blood cells with additive solution comprises pumping additive solution into the red blood cell flow path.

6. The method of claim 1 wherein the separated red blood cells and additive solution combination is pumped through the leukoreduction filter.