Removing bubbles in a microfluidic device
Methods of removing bubbles from a microfluidic device are described where the flow is not stopped. Methods are described that combine pressure and flow to remove bubbles from a microfluidic device. Bubbles can be removed even where the device is made of a polymer that is largely gas impermeable.
1. A method of using non-equilibrated culture media, comprising:
a) providing
i) culture media oversaturated with gas that has not been treated to physically remove dissolved gas from solution, and
ii) a microfluidic device comprising a microchannel with an inlet and an outlet, said microchannel comprising living cells attached thereto; and
b) flowing said culture media at a flow rate under a first applied pressure at said inlet and a second applied pressure at said outlet over a period of time through said microchannel over said cells, said flowing comprising using a first pressure means to apply a first pressure to said flowing culture media at said inlet, and using a second pressure means to apply a second pressure to said flowing culture media at said outlet, wherein said first applied pressure is greater than said second applied pressure and wherein living cells are in said microchannel after said period of time.
2. The method of claim 1 , wherein said inlet of said microchannel is in fluidic communication with a first reservoir and wherein said outlet of said microchannel is in fluidic communication with a second reservoir.
3. The method of claim 2 , wherein said first reservoir comprises fluid under a first pressure and said second reservoir comprises fluid under a second pressure, wherein said first pressure is greater than said second pressure.
4. The method of claim 2 , wherein said first applied pressure is greater than said second applied pressure by at least 0.5 kPa.
5. The method of claim 2 , wherein said first applied pressure is greater than said second applied pressure by less than 2 kPa.
6. The method of claim 3 , wherein said first applied pressure is 34 kPa and said second applied pressure is 33 kPa.
7. The method of claim 1 , wherein said flowing of said culture media is at a flow rate of 40 uL/hr and no bubbles are visible in said microchannel.
8. The method of claim 1 , wherein said culture media has a temperature below room temperature.
9. The method of claim 1 , wherein said culture media has a temperature below 37° C.
10. A method of using culture media, comprising:
a) providing
i) culture media oversaturated with gas, said culture media having a temperature that is lower than 37° C., and
ii) a microfluidic device comprising a microchannel, said microchannel comprising living cells attached thereto; and
b) flowing said culture media at a flow rate under pressure over a period of time through said microchannel over said cells, without stopping said flowing of said fluid, such that, after said period of time, living cells are in said microchannel and no bubbles are visible in said microchannel.
11. The method of claim 10 , wherein said microchannel is in fluidic communication with a first reservoir at a first end of said microchannel, and a second reservoir at a second end of said microchannel.
12. The method of claim 11 , wherein said first reservoir comprises fluid under a first pressure and said second reservoir comprises fluid under a second pressure, wherein said first pressure is greater than said second pressure.
13. The method of claim 12 , wherein said first pressure is greater by at least 0.5 kPa.
14. The method of claim 12 , wherein said first pressure is greater by less than 2 kPa.
15. The method of claim 12 , wherein said first pressure is 34 kPa and said second pressure is 33 kPa.
16. The method of claim 10 , wherein said flowing of said culture media is at a flow rate of 40 uL/hr.
17. A method of using culture media, comprising:
a) providing
i) culture media oversaturated with gas, said culture media having a temperature that is from room temperature to 37° C., and
ii) a microfluidic device comprising a microchannel comprising an inlet and outlet, said microchannel comprises living cells attached thereto; and
b) flowing said culture media at a flow rate under a first applied pressure at said inlet and a second applied pressure at said outlet over a period of time through said microchannel over said cells such that, after said period of time, living cells are in said microchannel, wherein said first applied pressure is greater than said second applied pressure.
18. The method of claim 17 , wherein said inlet of said microchannel is in fluidic communication with a first reservoir, and said outlet of said microchannel is in fluidic communication with a second reservoir.
19. The method of claim 18 , wherein said first reservoir comprises fluid under a first pressure and said second reservoir comprises fluid under a second pressure, wherein said first pressure is greater than said second pressure.
20. A method of using culture media, comprising:
a) providing
i) culture media oversaturated with gas, said culture media having a temperature that is from room temperature to 37° C., and
ii) a microfluidic device comprising a microchannel comprising an inlet and an outlet; and
b) flowing said culture media at a flow rate under a first applied pressure at said inlet and a second applied pressure at said outlet over a period of time through said microchannel such that, after said period of time, no bubbles are visible in said microchannel.
21. The method of claim 20 , wherein said inlet of microchannel is in fluidic communication with a first reservoir, and said outlet of said microchannel is in fluidic communication with a second reservoir.
22. The method of claim 21 , wherein said first reservoir comprises fluid under a first pressure and said second reservoir comprises fluid under a second pressure, wherein said first pressure is greater than said second pressure.
23. The method of claim 1 , wherein said gas is selected from air, oxygen and a mixture of oxygen and nitrogen.
24. The method of claim 10 , wherein said gas is selected from air, oxygen and a mixture of oxygen and nitrogen.
25. The method of claim 17 , wherein said gas is selected from air, oxygen and a mixture of oxygen and nitrogen.
26. The method of claim 1 , wherein said living cells are selected from motor neuron cells and intestinal cells.
27. The method of claim 10 , wherein said living cells are selected from motor neuron cells and intestinal cells.
28. The method of claim 17 , wherein said living cells are selected from motor neuron cells and intestinal cells.
29. The method of claim 1 , wherein said culture media oversaturated with gas is at a temperature from room temperature to 37° C.
30. The method of claim 10 , wherein said culture media oversaturated with gas is at a temperature from room temperature to 37° C.