Pipette tip and liquid injection method

• US 10,639,625 B2
• Filed: 03/23/2018
• Issued: 05/05/2020
• Est. Priority Date: 09/28/2015
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Kuniyasu, Toshiaki, Kimura, Toshihito, Nishio, Tomonori, Nishijima, Kazuteru
• Primary Examiner(s): Warden, Jill A
• Assistant Examiner(s): Fisher, Brittany I
• Application Number:
  US15/933,690
• Publication Number:
  US 20180207633A1
• Time in Patent Office: 774 Days
• Field of Search: 422525, 422545
• CPC Class Codes: B01L 2200/025 Align devices or objects to ensure defined positions relative to each other
• CPC Class Codes: B01L 2200/0615 Loss of fluid by dripping
• CPC Class Codes: B01L 2200/141 Preventing contamination, tampering
• CPC Class Codes: B01L 3/02 Burettes; Pipettes
• CPC Class Codes: B01L 3/0217 of the plunger pump type medical syringes A61M
• CPC Class Codes: B01L 3/0275 Interchangeable or disposable dispensing tips
• CPC Class Codes: B04B 11/00 Feeding, charging, or discharging bowls B04B1/00, B04B3/00, B04B7/04 take precedence
• CPC Class Codes: B04B 5/02 Centrifuges consisting of a plurality of separate bowls rotating round an axis situated between the bowls
• CPC Class Codes: G01N 2035/103 using disposable tips
• CPC Class Codes: G01N 35/10 Devices for transferring samples or any liquids to, in, or from, the analysis apparatus, e.g. suction devices, injection devices G01N35/0099 takes precedence

Abstract

A pipette tip includes a body and projections. In the body, a flow passage in which liquid from the syringe flows and an ejection opening that ejects the liquid, which has flowed through the flow passage, to the outside are formed. The ejection opening is formed in a distal end portion. The projections are provided on the distal end portion and protrude from a region around the ejection opening in the ejection direction of liquid. The projections are partially disposed around the central axis of the body. Even in a case where a residual droplet adheres to the ejection opening, the residual droplet does not adhere to an injection opening of a sample container, because the projections guard a region around the residual droplet.

Claims

1. A pipette tip comprising:

a tubular body having a distal end portion in which an ejection opening that ejects liquid from an injector is formed; and

at least one projection that is provided on the distal end portion and that projects from a region around the ejection opening in an ejection direction of the liquid, the projection being partially disposed around an axis of the body,

wherein the at least one projection is provided on a distal end surface of a rib provided on an outer peripheral surface of the distal end portion around the axis, and

wherein the projection is provided in such a way that a gap is not formed between an inner peripheral surface of the at least one projection and the outer peripheral surface of the distal end portion around the axis in a width direction perpendicular to an axial direction of the distal end portion.

2. The pipette tip according to claim 1, wherein a plurality of projections are provided, and

wherein the plurality of projections are disposed at intervals around the axis.

3. The pipette tip according to claim 2, wherein the plurality of projections are disposed at regular intervals.

4. The pipette tip according to claim 3, wherein the at least one projection has a columnar shape extending in a longitudinal direction that is the ejection direction.

5. The pipette tip according to claim 4, wherein the at least one projection has a cylindrical columnar shape.

6. The pipette tip according to claim 2, wherein the at least one projection has a columnar shape extending in a longitudinal direction that is the ejection direction.

7. The pipette tip according to claim 6, wherein the at least one projection has a cylindrical columnar shape.

8. The pipette tip according to claim 7, wherein a distal end of the at least one projection is rounded.

9. The pipette tip according to claim 1, wherein the at least one projection has a columnar shape extending in a longitudinal direction that is the ejection direction.

10. The pipette tip according to claim 9, wherein the at least one projection has a cylindrical columnar shape.

11. The pipette tip according to claim 10, wherein a distal end of the at least one projection is rounded.

12. The pipette tip according to claim 1, wherein an occupancy ratio of the at least one projection to an entire circumference around the axis is in a range of 3% to 10%.

13. The pipette tip according to claim 1, wherein the at least one projection has a tapered shape whose diameter decreases from a proximal end side toward a distal end thereof.

14. The pipette tip according to claim 1, wherein an anticoagulant for suppressing coagulation of the liquid is applied to a flow passage in the body through which the liquid from the injector flows toward the ejection opening.

15. The pipette tip according to claim 1, wherein the distal end portion and the at least one projection are integrally formed.

16. A liquid injection method using a pipette tip according to claim 1, the method comprising:

attaching the pipette tip to the injector;

inserting the distal end portion of the pipette tip into an injection opening of a sample container; and

injecting the liquid into the sample container from the injector.

17. The liquid injection method according to claim 16, wherein the pipette tip satisfies a condition DL/2≤

RG,

where DL is a maximum width of a residual droplet in a radial direction of the ejection opening, the residual droplet being a droplet that protrudes from the ejection opening in the ejection direction and that remains, and RG is a distance from a center of the ejection opening to the projection in the radial direction.

18. The liquid injection method according to claim 16, wherein the pipette tip satisfies a condition HL≤

HG,

where HL is a maximum length of a residual droplet in the ejection direction, the residual droplet being a droplet that protrudes from the ejection opening in the ejection direction and that remains, and HG is a length of the projection in the ejection direction.

19. The liquid injection method according to claim 16, wherein the injector is used to inject blood into a sample container for centrifugal separation, the blood having been sampled from a living body.