Pipette tip adapter

Abstract

An adapter for connecting an array of pipette tips having through bores with conical upper ends to a multichannel air displacement pipettor having a plurality of ports with compliant internal sealing surfaces. The adapter comprises a planar base with an array of openings extending between its top and bottom surfaces. Sealing tubes project upwardly from the top surface, and tip mounting tubes project downwardly from the bottom surface, with pairs of sealing tubes and tip mounting tubes being arranged coaxially and in communication with respective ones of the openings in the base. The tip mounting tubes are externally dimensioned and configured for insertion into the conical upper ends of the pipette tips, and the sealing tubes are externally configured and dimensioned for insertion into the ports of the pipettor and into sealing interengagement with their compliant internal sealing surfaces.

Claims

1. An assembly, comprising a pipette tip adapter, an array of pipette tips and a head of a multichannel pipettor; the adapter comprising: a planar base comprising an array of openings extending between a top surface and a bottom surface of the base; proximal tubes each comprising a cylindrical exterior wall projecting upwardly from the top surface of the base, wherein each of the openings of the base is in connection with the interior of one of the proximal tubes; distal tubes projecting downwardly from the bottom surface of the base, wherein each of the openings of the base is in connection with the interior of one of the distal tubes; the array of pipette tips comprising a plurality of pipette tips, wherein each of the pipette tips in the array of pipette tips is connected to one of the distal tubes of the adapter; and the head of the multichannel pipettor comprising an array of cylinders each terminating in a port lined with an o-ring comprising a compliant internal sealing surface; wherein: each of the proximal tubes of the adapter is inserted into a corresponding port of the head of the multichannel pipettor, and the cylindrical exterior wall of each of the proximal tubes is in contact with the compliant internal sealing surface of a corresponding o-ring in each corresponding port.

2. The assembly of claim 1, wherein the base comprises a network of upper reinforcing ribs connected to the top surface.

3. The assembly of claim 2, wherein the proximal tubes project upwardly above the upper reinforcing ribs.

4. The assembly of claim 1, wherein the base comprises a network of lower reinforcing ribs connected to the bottom surface.

5. The assembly of claim 4, wherein the distal tubes project downwardly below the lower reinforcing ribs.

6. The assembly of claim 1, wherein the distal tubes each comprise a hollow truncated cone.

7. The assembly of claim 1, wherein the proximal tubes each comprise a cylindrical wall with a tapered upper end.

8. The assembly of claim 7, wherein the proximal tubes each comprise a cylindrical wall with a chamfered upper end.

9. The assembly of claim 1, wherein each of the proximal tubes is arranged coaxially with one of the openings of the base.

10. The assembly of claim 1, wherein each of the distal tubes is arranged coaxially with one of the openings of the base.

11. The assembly of claim 9, wherein each of the distal tubes is arranged coaxially with one of the openings of the base.

12. The assembly of claim 2, wherein the base comprises a network of lower reinforcing ribs connected to the bottom surface.

13. The assembly of claim 1, wherein the proximal tubes are hollow.

14. The assembly of claim 6, wherein the proximal tubes are hollow.

15. The assembly of claim 1, wherein each of the pipette tips in the array of pipette tips is in sealing engagement with one of the distal tubes.

16. The assembly of claim 1, wherein each of the proximal tubes projects the same distance from the top surface of the base.

17. The assembly of claim 1, wherein each of the proximal tubes comprises an outer diameter that is less than an outer diameter of each of the distal tubes.

18. The assembly of claim 1, consisting of a single polymer.

19. The assembly of claim 1, wherein the proximal tubes and the distal tubes are arranged in an array of rows and columns.

20. The assembly of claim 1, wherein each of the cylinders in the array of cylinders comprises a corresponding piston.

21. The assembly of claim 20, wherein each of the cylinders is configured for reciprocal movement within the corresponding piston.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a top perspective view of a pipette tip adapter in accordance with an exemplary embodiment of the present invention;

(2) FIG. 2 is a top view of the pipette tip adapter;

(3) FIG. 3 is a bottom perspective view of the pipette tip adapter;

(4) FIG. 4 is a bottom view of the pipette tip adapter;

(5) FIG. 5 is a bottom perspective view showing the pipette tip adapter attached to an array of pipette tips;

(6) FIG. 6 is a partial sectional view through the pipette tip adapter and attached pipette tips;

(7) FIG. 7 is a perspective view of a multichannel air displacement pipettor designed to employ the pipette tip adapter of the present invention;

(8) FIG. 8 is a sectional view on an enlarged scale taken through the operating head of the pipettor shown in FIG. 7, and showing the pistons fully withdrawn;

(9) FIG. 9 is an enlarged view of a portion of the illustration in FIG. 8; and

(10) FIG. 10 is a view similar to FIG. 8, showing the pistons of the pipettor partially advanced.

DETAILED DESCRIPTION

(11) With reference initially to FIGS. 1-6, a pipettor tip adapter in accordance with an exemplary embodiment of the present invention is generally indicated at 10. The pipette tip adapter comprises a planar base 12 with an array of openings 14 extending between bottom and top surface 16, 18 of the base.

(12) Sealing tubes indicated typically at 20 project upwardly from the top surface 16, and tip mounting tubes indicated typically at 22 project downwardly from the bottom surface 18. Pairs of sealing tubes 20 and mounting tubes 22 are arranges coaxially and in communication with respective ones of the openings 14 in the base 12.

(13) The sealing tubes 20 and tip mounting tubes 22 may be arranged in an array of rows and columns. The spacing of the rows and columns matches the commonly available tip spacing of both multichannel pipettors and associated racks found in the marketplace. These in turn match the well positions of commonly available microtiter plates. Nine and four and a half millimeters are two common spacing distances. By way of example, a 96 channel pipettor has twelve rows and eight columns of tips on nine millimeter spacing, while a 384 channel pipettor has a twenty four by sixteen matrix on a four and a half millimeter spacing. This invention can also be used in a one-dimensional array format. For example, a single row of twelve on a nine mm spacing.

(14) As can be best seen in FIG. 6, the tip mounting tubes 22 comprise truncated conical cones configured and dimensioned for insertion and sealing interengagement with the conical upper ends 24 of pipette tips 26. FIG. 5 shows an array of pipette tips 26 secured to the tip mounting tubes of the adapter.

(15) Base 12 may be advantageously strengthened by a network of upper reinforcing ribs 28 on its top surface 16, and/or a similar network of lower reinforcing ribs 30 on its bottom surface 18. The sealing tubes 20 may be located where the upper reinforcing ribs 28 converge, whereas the tip mounting tubes 22 may be located in areas of the bottom surface bracketed by the lower reinforcing ribs 30.

(16) The sealing tubes 20 have cylindrical walls with chamfered upper ends 20a. The tip mounting tubes 22 project downwardly below the lower reinforcing ribs 30, and the sealing tubes 20 project upwardly above the upper reinforcing ribs 28.

(17) With reference to FIG. 7, a multichannel air displacement pipettor is generally indicated at 32. The head 34 of the pipettor is designed to accept the pipette adapter 10 of the present invention. To this end, the pipette adapter may be provided with laterally extending rails 36 which are designed to slide into receiving slots in the pipettor head. Tabs 35 also may be provided to facilitate handling the adapter.

(18) As shown in FIGS. 8 and 10, the pipettor head has an array of cylinders indicated typically at 38 matching the array of sealing tubes 20 of the tip adapter 10. The cylinders 38 lead to ports lined with O-rings providing compliant internal sealing surfaces. Although O-rings 40 are shown, any equivalent compliant seal material and appropriate geometry could be employed. For example, a sheet of elastomeric material with a matrix of aligned bore holes could be employed.

(19) The chamfered upper ends 20a of the sealing tubes serve to lower the insertion forces of the sealing tubes into the ports of the pipettor cylinders 38 while also reducing wear and tear of the O-rings 40 or other like compliant sealing surfaces.

(20) Pistons indicated typically at 42 are arranged for reciprocal movement in the cylinders 38. In FIG. 8, the pistons 42 are withdrawn in the cylinders 38 away from the adapter 10, and in FIG. 10, the pistons are shown advanced in the cylinders.

(21) The tip adapter 10 is preferably injection molded using standard tooling methods and common processing techniques. Materials can include any rigid injection moldable polymer, with polypropylene being preferred. Additionally, a polymer with an internal lubricant that blooms to the surface of the part is preferable because the presence of the lubricant on the surface will reduce insertion forces and wear and tear on the seals.

(22) The exemplary embodiment herein described is preferably disposable. A non-disposable version is also possible, its design being essentially identical but produced from a material that is more robust and autoclavable. In such a design, the tips are installed to the adapter by the user with a dedicated fixture.

(23) To reduce the capital cost required to build injection molds, multiple tip size geometries can be accommodated in a single adapter by arranging the tip mounting tubes in a tiered geometry, where the larger tips fit on one tier and the smaller tips on a second tier.

(24) Often, disposable pipette tips incorporate filters. The purpose of the filter is to avoid aerosol contamination of the pipette mechanism by the liquid being pipetted. The pipette tip adapter of the present invention may be configured to accept such filters, thereby eliminating the need to use expensive tips with filters pre-installed in them.

(25) In light of the above, it will now be appreciated by those skilled in the art that the adapter of the present invention offers significant and heretofore unavailable advantages. The chamfered upper ends 20a of the sealing tubes 20 interact with the O-rings or equivalent compliant sealing materials to beneficially reduce the forces required to connect the pipette tips to the pipettor. For example, in the case of a 96 channel pipettor, the adapter's sealing tubes 20 can be successfully inserted into the cylinder ports of the pipettor with a minimal coupling force on the order of 10 lbs. This can be accomplished safely without exposing an operator to potential injury.

(26) The adapter base 12, preferably when strengthened by the upper and/or lower reinforcing ribs 28, 30, provides a rigid platform supporting the tip mounting tubes 22 and sealing tubes 20. Thus, the adapter can be pressed onto an array of pipette tubes without undergoing deflection that might otherwise compromise uniform and reliable sealed insertion of the tip mounting tubes 22. This same rigidity, when coupled with the minimal coupling forces referenced above, results in a more uniform and reliable insertion of the sealing tubes into the pipettor cylinder ports.

(27) Higher forces may be required to install the pipette tips on the adapter, but this can be accomplished in a factory setting prior to supplying the loaded adapter to a user, or by the user with a specially designed press incorporating appropriate safety features.

(28) While exemplary embodiments of the invention have been disclosed, modification, additions and deletions can be made without departing from the spirit and scope of the inventions as set forth in the following claims.