Methods and apparatus for cell culture array

1. A microfluidic culture system for providing an environment for one or more of biologic growth or analysis or manipulation, the system comprising:

(a) a plurality of culture units, at least one of said culture units comprising:

(i) a culture area having a culture area inlet, the culture area inlet configured to allow passage of cells or other culture objects into the culture area; and

(ii) a flow channel having a flow channel inlet and a separate flow channel outlet, the flow channel inlet, the flow channel outlet, and the flow channel separated from the culture area and the culture area inlet by:

(1) a micro fluidic passage structure substantially surrounding the culture area and positioned between the culture area and the flow channel;

(2) wherein the micro fluidic passage structure comprises one or more micro passages providing fluidic connection between the flow channel and the culture area;

(b) wherein the micro fluidic passage structure separates the flow channel inlet from the culture area inlet and the culture area;

(c) wherein the micro fluidic passage structure separates the flow channel outlet from the culture area inlet and the culture area;

(d) wherein the micro fluidic passage structure is configured to prevent culture objects from passing between the flow channel and the culture area; and

(e) wherein the flow channel is configured such that fluid input in the flow channel inlet flows to the flow channel outlet without passing through the culture area inlet while the fluid is in fluidic communication with the culture area through the micro fluidic passage structure.

2. The system of claim 1 :

wherein the flow channel is configured to allow a fluidic connection from the flow channel inlet to the flow channel outlet around the micro fluidic passage structure surrounding the culture area without requiring fluid to pass through the micro passage structure; and

wherein the micro fluidic passage structure is configured to resist fluidic flow between the flow channel and the culture area thereby allowing fluidic mass transport by diffusion without substantially impeding fluidic flow in the flow channel.

3. The system of claim 2 , wherein said micro fluidic passage structure acts as a virtual membrane by resisting fluidic flow between said flow channel and said culture area.

4. The system of claim 1 :

wherein the micro passages are arranged in a grid-like structure; and

wherein said micro fluidic passage structure comprises a plurality of intersecting micro passages.

5. The system of claim 1 , wherein the flow channel is configured to provide fluid flow around the culture area, from the flow channel inlet to the flow channel outlet, substantially perpendicular to the micro passages.

6. The system of claim 1 :

wherein said micro fluidic passage structure comprises a plurality of micro passages, each approximately between 0.25 to 10 μm wide; and

wherein said flow channel comprises at least one flow channel that is between 20 and 200 μm high.

7. The system of claim 1 , further comprising:

at least three ports for fluidic access to a microchamber;

wherein a first two ports are configured to provide continuous perfusion of a medium to the culture area through said micro fluidic passage structure for sustaining growth; and

wherein a third port is configured to load or remove or both load and remove a cell or cells, beads, or other objects for culture.

8. The system of claim 1 , further comprising:

a plurality of culture areas each having a culture area input;

wherein a flow channel output surrounding one culture area unit is fluidically continuous with a flow channel input of an adjacent culture area.

9. The system of claim 1 , further comprising:

a well plate comprising a plurality of fluid access wells;

wherein each culture unit is connected to at least three wells, a first well fluidically connected to a culture area inlet, a separate second well connected to a flow channel inlet, and a third well connected to a flow channel output thereby providing at least three separate external fluidic access points to said culture units.

10. The system of claim 1 , wherein said culture units comprise microchambers that are approximately 0.2 to 4 mm in diameter or width and approximately 20 to 100 μm in height.

11. The system of claim 10 :

wherein said culture units comprise micro passages that are smaller than the size of cells handled and effectively prevent cells from being flushed away or from migrating outside the chamber; and

wherein said micro passages provide uniform nutrient access inside the microchamber from adjacent fluid flow in said flow channel.

12. The system of claim 10 , wherein said microchambers are approximately circular.

13. The system of claim 10 , wherein said microchambers have an extended approximately rectangular shape or wherein said microchambers are approximately U shaped.

14. The system of claim 1 , further comprising:

a microchamber having an inlet port and substantially surrounded by a chamber wall, said chamber wall comprising a diffusion micro structure; and

a continuous medium flow channel adjacent to at least one-half of said chamber wall providing unimpeded fluid flow adjacent to said chamber wall such that material in said flow channel is exchanged with said chamber through diffusion.

15. The system of claim 14 , wherein said diffusion micro structure has a high fluidic resistance ratio to said flow channel and said microchamber.

16. The system of claim 1 , further comprising:

a set of one or more micro-sized units;

wherein at least one said micro-sized units comprises:

a microchamber or a microchannel;

a single large volume inlet port;

a flow-around channel proximate to said microchamber or microchannel and connected thereto by one or more micro diffusion structures;

wherein medium or reagents in said flow-around channel can enter said microchamber and waste can exit said microchamber into said flow-around channel by diffusion or other mass transfer through said micro diffusion structures.