Aerosol and liquid transfer resistant pipette tip apparatus

• US 5,580,529 A
• Filed: 06/12/1995
• Issued: 12/03/1996
• Est. Priority Date: 04/22/1994
• Status: Expired due to Term

• Current Assignee: Bio-Plas Incorporated
• Original Assignee: Bio-Plas Incorporated
• Inventors: Smith, James C., DeVaughn, Donald H.
• Primary Examiner(s): Le, Long V.
• Application Number:
  US08/489,506
• Time in Patent Office: 540 Days
• Field of Search: 422/99, 422/100, 422/101, 422/103, 436/177, 436/180, 73/864.03, 73/864.11, 73/864.14, 210/473, 210/477
• US Class Current: 422/525
• CPC Class Codes: B01L 3/0275 Interchangeable or disposable dispensing tips
• CPC Class Codes: G01N 2035/1023 using a valve in the tip or nozzle
• CPC Class Codes: Y10T 436/255 including use of a solid sorbent, semipermeable membrane, or liquid extraction
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

A baffle assembly (23) positioned between a pipetter assembly (10) and a disposable pipette tip (16) for substantially reducing transfer of aerosol and/or fluid specimens to the pipetter. The baffle assembly (23) includes a barrier structure (25) extending transversely across a receiving chamber (17) of the pipette tip (16) and defines at least one narrow passageway (26) extending generally in the direction of the longitudinal axis (27) through the barrier member (25) between an entrance (30) and an exit (31) thereof. The passageway (26) includes a first wall (32) extending generally transverse, and preferably perpendicular to, the longitudinal axis (27) of the pipette tip to define at least one elbow portion positioned between the entrance (30) and the exit (31) of the passageway. A filter membrane (55) preferably is secured across the passageway (26) to reduce aerosol transport through the passageway (26). A method for substantially reducing transfer of aerosol and/or fluid to the pipetter (10) is also provided, as is a method for securing the filter (55) to the baffle assembly (23).

Claims

1. A liquid baffle adapter assembly positioned between a pipetter assembly formed for drawing and dispensing a liquid, and a pipette tip device including a liquid drawing end and an opposite pipetter securing end formed for removably securement to a pipette tip mounting end of said pipetter assembly, said pipette tip device defining a liquid receiving chamber extending from said liquid drawing end to said pipetter securing end along a longitudinal axis thereof, said baffle adapter assembly comprising:

a barrier structure molded together with said adapter assembly as a unit, and defining a receiving bore formed and dimensioned for snug removable receipt of said tip mounting end of said pipetter assembly, and an opposite nose portion formed and dimensioned for snug removable engagement with said pipetter securing end of said pipette tip device, said barrier structure extending transversely across said pipette tip liquid receiving chamber and defining an elongated passageway extending in the direction of said longitudinal axis through said barrier structure between an entrance at said nose portion and an exit at said receiving bore, said passageway being defined by substantially vertical walls tapering inwardly from said entrance toward said exit, and having substantial surface area relative a transverse cross-sectional area of said passageway for condensing aerosol thereon upon contact with said vertical walls, said passageway further being narrow relative the passageway longitudinal length, and including a first wall portion extending substantially perpendicular from one of said vertical walls and extending substantially across said passageway, and a plurality of oppositely facing second wall portions axially spaced in a direction toward said entrance from said first wall portion and extending substantially perpendicularly from the other one of said vertical walls in a direction away from said passageway to define with said first wall portion a plurality of spaced apart elbow-shaped channels positioned in said passageway between said entrance and said exit.

2. The adapter assembly as defined in claim 1 wherein,

said nose portion tapers inwardly toward one distal end thereof, and

said receiving bore tapers outwardly toward an opposite distal end thereof.

3. The adapter assembly as defined in claim 1 wherein,

said passageway is of a length substantially greater than a width thereof.

4. The adapter assembly as defined in claim 3 wherein,

a ratio of said passageway length to said passageway width is at least about 10:

1.

5. The adapter assembly as defined in claim 3 wherein,

said vertical walls include an inner facing wall and an outer facing wall forming an annular-shaped passageway extending longitudinally through said barrier structure from said entrance and terminating proximate said exit.

6. The adapter assembly as defined in claim 1 wherein,

said elbow shaped channels each extends radially inwardly toward said longitudinal axis.

7. The adapter assembly as defined in claim 1 wherein,

said passageway includes at least two third wall portions extending generally parallel to said longitudinal axis from said second wall portions to define second elbow-shaped channels positioned sequentially with respect to the first named elbow-shaped channels between said entrance and said exit.

8. The adapter assembly as defined in claim 1 wherein,

said elbow-shaped channels are positioned proximate said receiving bore.

9. The adapter assembly as defined in claim 1 wherein,

said passageway exit terminates into a funnel portion defined by said barrier structure and extending into a bottom portion of said receiving bore, said funnel portion further tapering outwardly toward said pipetter mounting tip end.

10. The adapter assembly as defined in claim 1 wherein,

said passageway includes at least four independent, elbow-shaped channels, in parallel, positioned circumferentially about and extending in the direction of said longitudinal axis, each said channel being substantially narrower than said passageway, and each including said first wall portion extending generally perpendicular to said longitudinal axis to define the respective elbow-shaped channels positioned between said passageway entrance and said exit.

11. The adapter assembly as defined in claim 10 wherein,

said vertical walls include an inner facing wall and an outer facing wall forming an annular-shaped passageway communicating and intersecting each channel, and extending longitudinally along said barrier structure from said entrance and terminating proximate said exit.

12. The adapter assembly as defined in claim 10 wherein,

each said channel includes at least two third wall portions extending generally parallel to said longitudinal axis to define respective second elbow-shaped channels positioned sequentially with the respective first named elbow-shaped channels between said entrance and said exit.

13. The adapter assembly as defined in claim 1 further including:

an aerosol filter member coupled to said barrier structure and along said passageway in a manner substantially reducing transfer of aerosol from said receiving chamber to said pipette tip mounting end of the pipetter assembly.

14. The adapter assembly as defined in claim 13 wherein,

said aerosol filter member is disposed on the distal end of said nose portion.

15. The adapter assembly as defined in claim 14 wherein,

said distal end of said nose portion defines a fusing edge outwardly protruding therefrom and positioned proximate said passageway entrance, said fusing edge being adapted to fuse said aerosol filter member about a perimeter of the nose portion distal end.

16. The adapter assembly as defined in claim 15 wherein,

said fusing edge is heat deformable to fuse said filter member thereon, and extends continuously around said perimeter thereof.