CAPILLARY TRANSFER PIPETTES AND RELATED METHODS

• US 20180036725A1
• Filed: 08/08/2016
• Published: 02/08/2018
• Est. Priority Date: 08/08/2016
• Status: Active Grant

• Current Assignee: Nalge NUNC International Corporation (Perspecta, Inc.)
• Original Assignee: Nalge NUNC International Corporation (Perspecta, Inc.)
• Inventors: Le, Christopher, Escalante, Ilianna Maria
• Granted Patent: US 10,814,320 B2
• Time in Patent Office: Days
• CPC Class Codes: B01L 2200/0684 Venting, avoiding backpressure, avoid gas bubbles
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/028 Graduation
• CPC Class Codes: B01L 2300/0832 cylindrical, tube shaped
• CPC Class Codes: B01L 2300/0838 Capillaries
• CPC Class Codes: B01L 2300/161 Control and use of surface tension forces, e.g. hydrophobic, hydrophilic
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0481 squeezing of channels or chambers
• CPC Class Codes: B01L 3/021 Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids
• CPC Class Codes: B29C 2049/503 being independently movable during the mould closing
• CPC Class Codes: B29C 49/04 Extrusion blow-moulding
• CPC Class Codes: B29C 49/04104 extruding the material discontinuously
• CPC Class Codes: B29C 49/071 Preforms or parisons characterised by their configuration, e.g. geometry, dimensions or physical properties
• CPC Class Codes: B29C 49/50 having cutting or deflashing means
• CPC Class Codes: B29K 2101/12 Thermoplastic materials
• CPC Class Codes: B29K 2105/258 Tubular
• CPC Class Codes: B29K 2995/0092 hydrophilic
• CPC Class Codes: B29L 2031/753 Medical equipment; Accessories therefor bloodbags, medical bags B29L2031/7148; artificial eyes B29L2011/0008

Abstract

A capillary transfer pipette includes a draw tube having a distal end defining a draw tube opening through which liquid is drawn via capillary action, a proximal end, and a lumen. A squeeze bulb is arranged proximally of the draw tube and defines a fluid chamber in fluid communication with the lumen, the squeeze bulb being compressible to dispense drawn liquid from the draw tube. An air vent hole is formed in at least one of the draw tube or the squeeze bulb, and is configured to vent air to facilitate drawing of liquid through the draw tube opening via capillary action. A volume indicating element may be provided on the draw tube, and the air vent hole may be located proximally of the volume indicating element. The lumen may be formed with a first diameter at the proximal end and a differing second diameter at the distal end. Methods of collecting liquid with, and of making, a capillary transfer pipette are also disclosed.

Claims

1. A capillary transfer pipette, comprising:

a draw tube having a distal end defining a draw tube opening through which liquid is drawn via capillary action, a proximal end, and a lumen extending therebetween;

a squeeze bulb arranged proximally of the draw tube and defining a fluid chamber in fluid communication with the lumen, the squeeze bulb being compressible to dispense drawn liquid from the draw tube;

an air vent hole formed in at least one of the draw tube or the squeeze bulb and configured to vent air therethrough to facilitate drawing of liquid through the draw tube opening via capillary action; and

at least one volume indicating element provided on the draw tube.

2. The capillary transfer pipette of claim 1, wherein the at least one volume indicating element projects radially outward from the draw tube.

3. The capillary transfer pipette of claim 1, wherein the air vent hole extends through the at least one volume indicating element.

4. The capillary transfer pipette of claim 1, wherein the at least one volume indicating element includes a plurality of volume indicating elements spaced along the draw tube, the air vent hole being located proximally of the distal-most volume indicating element.

5. The capillary transfer pipette of claim 4, wherein the air vent hole is located proximally of the proximal-most volume indicating element.

6. The capillary transfer pipette of claim 1, wherein the air vent hole is formed in the draw tube.

7. The capillary transfer pipette of claim 1, wherein the air vent hole is formed in the squeeze bulb.

8. The capillary transfer pipette of claim 1, wherein the capillary transfer pipette is formed from a polymeric material.

9. The capillary transfer pipette of claim 1, wherein the capillary transfer pipette is formed from a hydrophilic material.

10. The capillary transfer pipette of claim 1, further comprising:

at least one fin extending longitudinally and having a distal end spaced proximally from the draw tube opening.

11. The capillary transfer pipette of claim 10, wherein the distal end of the at least one fin is arranged so as to not extend distally beyond the air vent hole.

12. A capillary transfer pipette, comprising:

a draw tube having a distal end defining a draw tube opening through which liquid is drawn via capillary action, a proximal end, and a lumen extending therebetween, wherein the lumen is formed with a first diameter at the proximal end and a differing second diameter at the distal end;

a squeeze bulb arranged proximally of the draw tube and defining a fluid chamber in fluid communication with the lumen, the squeeze bulb being compressible to dispense drawn liquid from the draw tube; and

an air vent hole formed in at least one of the draw tube or the squeeze bulb and configured to vent air therethrough to facilitate drawing of liquid through the draw tube opening via capillary action.

13. The capillary transfer pipette of claim 12, wherein a distal end portion of the lumen tapers radially inward in a direction toward the distal end.

14. The capillary transfer pipette of claim 12, wherein a distal end portion of the lumen flares radially outward in a direction toward the distal end.

15. A capillary transfer pipette, comprising:

a draw tube having a distal end defining a draw tube opening through which liquid is drawn via capillary action, a proximal end, and a lumen extending therebetween;

a squeeze bulb arranged proximally of the draw tube and defining a fluid chamber in fluid communication with the lumen, the squeeze bulb being compressible to dispense drawn liquid from the draw tube;

at least one volume indicating element provided on the draw tube; and

an air vent hole located proximally of the at least one volume indicating element and configured to vent air therethrough to facilitate drawing of liquid through the draw tube opening via capillary action.

16. The capillary transfer pipette of claim 15, wherein the air vent hole is formed in the draw tube.

17. The capillary transfer pipette of claim 15, wherein the air vent hole extends through the at least one volume indicating element.

18. The capillary transfer pipette of claim 15, wherein the at least one volume indicating element includes a plurality of volume indicating elements, and the air vent hole is located proximally of the distal-most volume indicating element.

19. The capillary transfer pipette of claim 18, wherein the air vent hole is located proximally of the proximal-most volume indicating element.

20. The capillary transfer pipette of claim 15, wherein the air vent hole is formed in the squeeze bulb.

21. A method of collecting liquid with a capillary transfer pipette having a draw tube and an air vent hole, the method comprising:

positioning a distal opening of the draw tube in contact with a liquid to be drawn via capillary action;

drawing the liquid into the draw tube via capillary action; and

selectively obstructing the air vent hole when a proximal surface of the drawn liquid reaches one of a plurality of volume indicating elements provided on the draw tube, so as to cease drawing of the liquid into the draw tube.

22. The method of claim 21, further comprising:

compressing a squeeze bulb of the capillary transfer pipette to dispense liquid from the draw tube.

23. The method of claim 21, wherein the air vent hole is located proximally of the distal-most volume indicating element.

24. A method of making a capillary transfer pipette, the method comprising:

extruding a parison of molten polymeric material;

positioning the parison within a mold cavity defined between first and second mold structures and having a cavity wall;

injecting air into the parison so that the parison expands within the mold cavity and conforms to the cavity wall to form a capillary transfer pipette, the mold cavity being shaped so as to provide the capillary transfer pipette with a draw tube configured to draw liquid via capillary action, a squeeze bulb arranged proximally of the draw tube and configured to be compressed to dispense drawn liquid from the draw tube, and at least one fin extending longitudinally; and

forming an air vent hole in at least one of the draw tube or the squeeze bulb, the air vent hole configured to vent air therethrough to facilitate drawing of liquid by the draw tube via capillary action.

25. The method of claim 24, wherein the mold cavity is shaped so as to provide the capillary transfer pipette with at least one volume indicating element when air is injected into the parison.

26. The method of claim 24, wherein forming the air vent hole includes piercing a wall of the parison while the parison is positioned within the mold cavity.