Microfluidic device and method of loading sample into the microfluidic device

1. A microfluidic device comprising:

a sample chamber in which a sample is accommodated, wherein the sample chamber comprises:

an introduction portion comprising a loading hole through which the sample is loaded;

an accommodation portion comprising a discharge hole; and

a neck portion which forms a boundary between the introduction portion and the accommodation portion and provides a capillary pressure for controlling flow of the sample between the introduction portion and the accommodation portion,

wherein a bottom surface of the introduction portion is inclined upward to the neck portion from the loading hole to prevent flowing backward of the sample, and

wherein a distance from a center of the microfluidic device to a sidewall of the sample chamber gradually increases from the neck portion to the discharge hole.

2. The microfluidic device of claim 1 , wherein the sample chamber further comprises a distance maintaining portion which maintains a distance between a front end part of a sample loader inserted in the loading hole and a bottom surface of the introduction portion, and the distance maintaining portion is disposed in the introduction portion.

3. The microfluidic device of claim 1 , wherein the sample chamber further comprises a backward flow prevention portion which protrudes from a bottom surface of the accommodation portion.

4. The microfluidic device of claim 3 , wherein the backward flow prevention portion is disposed in a direction that crosses a direction of a flow path of a sample flowing to the discharge hole.

5. The microfluidic device of claim 4 , wherein an end part of the backward flow prevention portions is inclined upward toward the discharge hole.

6. The microfluidic device of claim 1 , further comprising an analysis unit which is connected to the discharge hole of the accommodation portion, receives the sample accommodated in the sample chamber and analyzes the sample.

7. The microfluidic device of claim 6 , wherein the analysis unit comprises:

a sample measuring portion which is connected to the sample chamber and measures the sample; and

a sample detection chamber which is connected to the sample measuring portion and in which a portion of the sample exceeding a capacity of the sample measuring portion is accommodated.

8. The microfluidic device of claim 7 , wherein the analysis unit further comprises a surplus sample chamber which is connected to the sample detection chamber and in which a portion of the sample exceeding a capacity of the sample detection chamber is accommodated.

9. The microfluidic device of claim 7 , wherein the sample measuring portion separates the sample into a supernatant and a sedimentation material by a centrifugal force.

10. The microfluidic device of claim 9 , wherein the analysis unit further comprises:

a dilution chamber in which a dilution buffer is accommodated, which is connected to the sample measuring portion and to which the supernatant is supplied; and

a detection chamber in which a reagent is accommodated and to which a mixture of the supernatant and the dilution buffer is supplied from the dilution chamber.

11. The microfluidic device of claim 10 , wherein the analysis unit further comprises a measuring chamber which is disposed between the dilution chamber and the sample measuring portion and accommodates a fixed amount of the supernatant.

12. The microfluidic device of claim 11 , wherein the analysis unit further comprises a plurality of valves disposed in channels connecting the sample measuring portion, the measuring chamber, the dilution chamber, and the detection chamber, to control a flow of a fluid.

13. A microfluidic device comprising:

a sample chamber in which a sample is accommodated, wherein the sample chamber comprises an introduction portion comprising a loading hole through which the sample is loaded, and a neck portion which provides a capillary pressure for controlling flow of the sample between the introduction portion and the accommodation portion, wherein a bottom surface of the introduction portion is inclined upward to the neck portion from the loading hole to prevent flowing backward of the sample, and wherein a distance from a center of the microfluidic device to a sidewall of the sample chamber gradually increases from the neck portion to the discharge hole; and

an analysis unit which receives and analyzes the sample from the sample chamber,

wherein the analysis unit comprises:

a sample measuring portion which measures the sample; and

a sample detection chamber which is connected to the sample measuring portion and in which a portion of the sample exceeding a capacity of the sample measuring portion is accommodated; and

a surplus sample chamber which is connected to the sample detection chamber and in which a portion of the sample exceeding a capacity of the sample detection chamber is accommodated.

14. The microfluidic device of claim 13 , wherein the sample chamber further comprises an accommodation portion comprising a discharge hole, wherein the neck portion forms a boundary between the introduction portion and the accommodation portion.

15. The microfluidic device of claim 14 , wherein the sample measuring portion separates the sample into a supernatant and a sedimentation material by a centrifugal force.

16. The microfluidic device of claim 15 , wherein the analysis unit further comprises:

a dilution chamber in which a dilution buffer is accommodated, which is connected to the sample measuring portion and to which the supernatant is supplied; and

a detection chamber in which a reagent is accommodated and to which a mixture of the supernatant and the dilution buffer is supplied from the dilution chamber.

17. The microfluidic device of claim 16 , wherein the analysis unit further comprises a measuring chamber which is disposed between the dilution chamber and the sample measuring portion and accommodates a fixed amount of the supernatant.

18. The microfluidic device of claim 17 , wherein the analysis unit further comprises a plurality of valves disposed in channels connecting the sample measuring portion, the measuring chamber, the dilution chamber, and the detection chamber, to control a flow of a fluid.

19. A microfluidic device comprising: a sample chamber in which a sample is accommodated; and

an analysis unit which receives the sample from the sample chamber and comprises at

least one reaction chamber for analyzing the sample, wherein the sample chamber comprises: a loading hole through which the sample is loaded; a discharge hole which is connected to the analysis unit; and a neck portion comprising a capillary valve which is disposed between the loading hole and the discharge hole and passes the sample only when a predetermined pressure is applied to the sample, wherein the capillary valve comprises a protrusion formed by first and second inclined portions of a bottom surface of the sample chamber, and wherein a distance from the center of the microfluidic device to a sidewall of the sample chamber gradually increases from the neck portion to the discharge hole.

20. The microfluidic device according to claim 19 , wherein the sample chamber further comprises at least one backward flow prevention portion which protrudes from the bottom surface of the sample chamber at a position between the capillary valve and the discharge hole, and provides a flow resistance to the sample to impede the sample from flowing back towards the loading hole.