Fluid reservoir

1. A fluid reservoir comprising:

i) a funnel portion ( 2 ) comprising an open angle in the range of 25° to 35°, wherein the funnel portion has a wide inlet for receiving fluid and a narrow outlet ( 3 ) for draining fluid at a constant flow rate, wherein the wide inlet has an inner diameter in the range of 0.40 to 0.60 inches and the narrow outlet has an inner diameter in the range of 0.10 to 0.20 inches; and

ii) an attachment portion ( 1 ) in fluid communication with the funnel portion via the narrow outlet, wherein the attachment portion has a length in the range of 0.3 to 0.5 inches and an inner diameter in the range of 0.15 to 0.30 inches,

iii) two flanges ( 4 ) positioned 180° from one another and adjacent to the narrow outlet, wherein the flanges ( 4 ) are attached to and stick out perpendicularly from the outer surface of the funnel portion by 0.10 to 0.15 inches such that the fluid reservoir directly twists or snaps into an orifice of a manifold and the flanges guide or lock the fluid reservoir into a stable and sealed position, wherein the fluid reservoir holds a maximum volume of about 2 mL, and wherein the fluid reservoir dispenses or drains fluid at a rate in the range of 2 mL/hr to 25 mL/hr.

2. The fluid reservoir of claim 1 , wherein the fluid reservoir is in fluid communication with a microfluidic device.

3. A method of delivering fluid to a microfluidic device at a constant flow rate, comprising inputting fluid into a fluid reservoir of claim 2 .

4. The fluid reservoir of claim 1 , wherein the fluid reservoir is comprised of high-density polyethylene (HDPE).

5. The fluid reservoir of claim 1 , wherein the fluid reservoir is produced by a molding process.

6. The fluid reservoir of claim 1 , wherein the fluid reservoir is produced by a blow molding process.

7. A microfluidic chip connected to and in fluid communication with the fluid reservoir of claim 1 .

8. The microfluidic chip of claim 7 , wherein a manifold ( 6 ) is directly connected to the fluid reservoir.

9. The microfluidic chip of claim 7 , wherein a manifold ( 6 ) is connected to the fluid reservoir via an adaptor.

10. A manifold ( 6 ) connected to and in fluid communication with the fluid reservoir of claim 1 .

11. The manifold ( 6 ) of claim 10 , wherein the manifold is directly connected to the fluid reservoir.

12. The manifold ( 6 ) of claim 10 , wherein the manifold ( 6 ) is connected to the fluid reservoir via an adaptor ( 5 ).

13. The manifold ( 6 ) of claim 10 , wherein the manifold is in fluid communication with a microfluidic device.

14. The fluid reservoir of claim 1 , wherein the thickness of the walls of the fluid reservoir are in the range of 0.030 to 0.10 inches.

15. The fluid reservoir of claim 1 , wherein the fluid reservoir is made of a material that is inert to and which does not bind with or dissolve when contacted with biological fluids such as whole blood or cells suspended in media.

16. The fluid reservoir of claim 1 , wherein the fluid reservoir is comprised of one or more polymers selected from the group consisting of polyethylene, polypropylene and mixtures thereof.

17. An apparatus comprising a fluid reservoir of claim 1 connected to an adaptor ( 5 ), wherein the attachment portion ( 1 ) has a smooth inner surface that is fitted or sealed onto the adaptor ( 5 ).

18. The apparatus of claim 17 , wherein the adaptor is made of silicon.

19. A system comprising one or more apparatus of claim 17 , each fluid reservoir in fluid communication with a manifold, wherein the adaptor ( 5 ) is attached to an inlet on the manifold, creating a seal that is impervious to and does not leak liquid.

20. The system of claim 19 , wherein the manifold in fluid communication with a microfluidic device.

21. The system of claim 20 , wherein the fluid reservoir comprises a fluid sample comprising circulating tumor cells (CTCs) for delivery to the microfluidic device.

22. The system of claim 21 , wherein the dispensing or drainage rate of fluid from the fluid reservoir to the microfluidic device can be adjusted by adjusting the dispensing and withdrawal rates of one or more pumps driving fluid flow.

23. A method of delivering fluid to a microfluidic device at a constant flow rate, comprising inputting fluid into a fluid reservoir in the system of claim 19 .