Methods and devices for high throughput purification
Described herein are devices and methods for high throughput purification of particles. In some cases, methods and devices described herein can be used to remove erythrocytes and purify leukocytes and raise the quality of umbilical cord blood and other transplant grafts, thereby significantly improving patient outcomes.
1. A method for purifying leukocytes of a predetermined size from a sample comprising leukocytes and particles of less than the predetermined size wherein said particles of less than the predetermined size are platelets or red blood cells, the method comprising:
(a) applying at least 100 mL of the sample to a microfluidic device, wherein:
i) the device comprises an array of obstacles for separating cells and particles based on size, wherein:
aa) the array of obstacles is arranged in rows;
bb) each subsequent row of obstacles is shifted laterally with respect to a previous row;
cc) the obstacles differentially deflect said leukocytes to a first outlet where they are recovered, and particles in the sample of less than the predetermined size flow to a second outlet;
ii) the sample comprises a calcium chelating agent and a thrombin inhibitor which are together present at a concentration sufficient to inhibit clogging of the device; and
(b) flowing the sample through the device at a flow rate of at least 5 ml/min under conditions such that leukocytes are separated from particles of less than the predetermined size.
2. The method of claim 1 , wherein the calcium chelating agent comprises EDTA at a concentration of at least 5 mM.
3. The method of claim 2 , wherein the thrombin inhibitor comprises PPACK at a concentration of at least 40 μM.
4. The method of claim 1 , wherein the sample flows through the device at a rate of at least 4 cm/s.
5. The method of claim 1 , wherein said sample comprises peripheral blood.
6. The method of claim 1 , wherein said sample comprises umbilical cord blood or placental blood.
7. The method of claim 1 , wherein the volume of said sample is at least 300 ml and the sample flows through the device at a rate of at least 10 mL/min.
8. The method of claim 1 , wherein the sample is flowed through the device under conditions such that flow streams of different velocities are generated based on their proximity to the obstacles, thereby causing leukocytes to have a different trajectory than the particles of less than the predetermined size.
9. The method of claim 8 , wherein the calcium chelating agent comprises EDTA at a concentration of at least 5 mM.
10. The method of claim 9 , wherein the thrombin inhibitor comprises PPACK at a concentration of at least 40 μM.
11. The method of claim 10 , wherein the sample flows through the device at a rate of at least 4 cm/s.
12. The method of claim 8 , wherein said sample comprises peripheral blood.
13. The method of claim 8 , wherein said sample comprises umbilical cord blood or placental blood.
14. The method of claim 8 , wherein the volume of said sample is at least 300 ml and the sample flows through the device at a rate of at least 10 mL/min.