RHEOTAXIS-BASED SEPARATION OF MOTILE SPERM AND BACTERIA USING A MICROFLUIDIC CORRAL SYSTEM

• US 20190308192A1
• Filed: 04/03/2019
• Published: 10/10/2019
• Est. Priority Date: 04/09/2018
• Status: Active Grant

• Current Assignee: Cornell University
• Original Assignee: Cornell University
• Inventors: ABBASPOURRAD, Alireza, Zaferani, Meisam, Cheong, Soon Hon
• Granted Patent: US 11,491,485 B2
• Time in Patent Office: Days
• CPC Class Codes: B01L 2200/0652 Sorting or classification of particles or molecules
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/087 Multiple sequential chambers
• CPC Class Codes: B01L 2300/0877 Flow chambers
• CPC Class Codes: B01L 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2400/086 using baffles or other fixed flow obstructions
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• CPC Class Codes: B01L 3/502753 characterised by bulk separation arrangements on lab-on-a-chip devices, e.g. for filtration or centrifugation separation in general B01D; microapparatus for analysis using electrophoresis G01N27/44791; sample preparation G01N1/28
• CPC Class Codes: B01L 3/502761 specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads, for physically stretching molecules investigating characteristics of particles G01N15/00
• CPC Class Codes: C12N 1/02 Separating microorganisms from their culture media
• CPC Class Codes: C12N 1/20 Bacteria; Culture media therefor
• CPC Class Codes: C12N 5/061 Sperm cells, spermatogonia
• CPC Class Codes: C12N 5/0612 sorting of gametes, e.g. according to sex or motility

Abstract

The present application relates to a microfluidic system and its method for use for the separation of motile sperm from immotile sperm or motile bacteria from immotile bacteria. The system includes a housing having a first end, and a second end, with a passage connecting the first and second ends. There is an inlet at the first end of the housing for charging fluids into the passage and an outlet at the second end of said housing for discharging fluids from the passage. There are one or more corrals within the passage, each of the corrals including a closed side and a partially open side. The closed side of the corrals is closer to the first end than the partially open side, with the closed side and partially open side defining between them a confinement region suitable for retaining motile sperm or motile bacteria.

Claims

1. A microfluidic system for separation of motile sperm from immotile sperm or motile bacteria from immotile bacteria, said system comprising:

a housing having a first end and a second end and containing a passage connecting the first and second ends;

an inlet at the first end of said housing for charging fluids into the passage proximate to the first end of said housing;

an outlet at the second end of said housing for discharging fluids from the passage proximate to the second end of said housing, whereby fluid flows from said inlet, through the passage, and into said outlet; and

one or more corrals within the passage, each of said corrals comprising a closed side and a partially open side, wherein the closed side is closer to the first end than the partially open side with the closed side and partially open side defining between them a confinement region suitable for retaining motile sperm or motile bacteria.

2. The system of claim 1, wherein the system comprises a plurality of corrals spaced apart within the passage.

3. The system of claim 1, wherein the one or more corrals further comprise:

a wall member located opposite the closed end of the one or more corrals to define a pair of openings at opposite ends of the wall member leading to the confinement region.

4. The system of claim 1, wherein the one or more corrals have a convex polygonal configuration.

5. The system of claim 1, wherein the one or more corrals have a configuration selected from the group consisting of a C-shaped configuration, a triangular-shaped configuration, a rectangular configuration, a pentagonal configuration, an oval configuration, a square configuration, and a semicircular configuration.

6. The system of claim 1, wherein the one or more corrals comprise one or more retainers to maintain motile sperm or bacteria within the confinement region.

7. The system of claim 1, wherein the one or more corrals are configured and arranged within the passage to form a rheotactic region proximate to the partially open side of each of the one or more corrals.

8. The system of claim 1, wherein the corrals per system range from 1 to about 100 in number.

9. The system of claim 8, wherein there are a plurality of corrals spaced apart by a distance ranging from about 100 μ

m to about 1000 μ

m.

10. The system of claim 1, wherein each corral has a maximum exterior dimension of about 80 μ

m to about 1 mm.

11. The system of claim 1, wherein the confinement region has a maximum interior dimension from about 5 μ

m to about 2 mm.

12. The system of claim 1, wherein there are one or more gaps between the closed side and the partially open side with each gap ranging from about 10 μ

m to about 500 μ

m.

13. The system of claim 1 further comprising:

a pump positioned to move fluids within the passage from the first end of the housing to the second end of the housing.

14. A method for separation of motile sperm from immotile sperm or motile bacteria from immotile bacteria, said method comprising:

providing the system of claim 1;

providing a sperm-containing sample or a bacteria-containing sample; and

passing the sperm-containing sample or the bacteria-containing sample through the inlet, through the passage, and through the outlet of said system, whereby motile sperm or motile bacteria are retained within the one or more corrals, while immotile sperm or immotile bacteria are discharged through the outlet.

15. The method of claim 14, wherein the sample comprises sperm.

16. The method of claim 14, wherein the sample comprises bacteria.

17. The method of claim 14 further comprising:

recovering motile sperm or motile bacteria from the one or more corrals.

18. The method of claim 17, further comprising:

washing the sample prior to said recovering the motile sperm or motile bacteria.

19. The method of claim 17, wherein motile sperm are recovered.

20. The method of claim 17, wherein motile bacterial are recovered.

21. The method of claim 19 further comprising:

utilizing the recovered motile sperm in conjunction with an assisted reproductive technology.

22. The method of claim 14 further comprising:

controlling flow of the sample through the housing to selectively retain the sperm or the bacteria within the one or more corrals.

23. The method of claim 22, wherein the flow of sample through the housing is at a rate ranging from about 0.5 mL/hr to 500 mL/hr.