US3626762A - Method and apparatus for filling a capillary tube with liquid - Google Patents

Method and apparatus for filling a capillary tube with liquid Download PDF

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Publication number
US3626762A
US3626762A US849371A US3626762DA US3626762A US 3626762 A US3626762 A US 3626762A US 849371 A US849371 A US 849371A US 3626762D A US3626762D A US 3626762DA US 3626762 A US3626762 A US 3626762A
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United States
Prior art keywords
length
tubing
liquid
break
fluid
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Expired - Lifetime
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US849371A
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English (en)
Inventor
Saul R Gilford
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Gilford Instrument Laboratories Inc
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Gilford Instrument Laboratories Inc
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G01N1/10—Devices for withdrawing samples in the liquid or fluent state
    • G01N1/14—Suction devices, e.g. pumps; Ejector devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
    • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
    • B01L3/02—Burettes; Pipettes
    • B01L3/021—Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G01N1/10—Devices for withdrawing samples in the liquid or fluent state
    • G01N1/14—Suction devices, e.g. pumps; Ejector devices
    • G01N2001/1472—Devices not actuated by pressure difference
    • G01N2001/149—Capillaries; Sponges

Definitions

  • Application Ser. No. 781,386 contemplates the mounting of a plurality of lengths of tubing in an evacuated vessel, with one end of each length open in the vessel so that when liquid is introduced to the vessel, at the top thereof, the liquid will be drawn into the lengths of tubing.
  • Application Ser. No. 830,185 relates to a method and apparatus whereby a plurality of lengths of pre-evacuated capillary tubing is mounted in a vessel, with the ends protruding into a well.
  • the liquid to be sampled is introduced into the well, the upper ends of the lengths of tubing being thereafter broken off below the level of the liquid to enable the contained vacuum to draw quantities of liquid into the respective lengths of tubing.
  • These upper lengths are pre-scored to enable clean breaking of the upper ends.
  • the field of the invention is micro-sampling and has this in common with all of the co-pending applications. But for the basic application Ser. No. 472,294, the copending applications are primarily concerned with the handling of a plurality of lengths of capillary tubing, although not being limited thereto.
  • the apparatus disclosed for handling a plurality of lengths is, however, not convenient or economical in the event that the technician wishes to work with a single length. Since the type of tubing which is used for sampling is quite fragile, difliculties in handling the same have arisen.
  • the invention cures these difliculties making it a sim- Patented Dec. 14, 1971 ple matter to fill a single length of capillary tubing for sampling or the like purpose.
  • the method and apparatus of the invention are applicable to biological and industrial fluids, and suitable for use in general laboratory work in biology, chemistry, industry, for quality control, etc.
  • the filled length does not have to be held in a horizontal position in order to prevent the loss of liquid, and 0bviously does not have to be held horizontally or even slanted downward away from the source in order to fill it, as often is required in conventional handling of openended capillary tubing.
  • the desirability of handling very small quantities of fluid by carefully cutting accurate short lengths of a longer length of capillary tubing containing the fluid will be understood from the disclosure of the co-pending applications.
  • the invention herein makes it advantageous even in the case where single lengths are being handled in laboratory, testing or quality control work.
  • the invention provides a method and apparatus which will assure easy handling without contamination and with a minimum chance of breakage.
  • the length of capillary tubing which is to be used is evacuated and its ends flamesealed, thereby containing the vacuum.
  • a score line is made by any suitable device adjacent one end 'of the length. This latter length is immersed into a body of the liquid with which it is desired to fill the length of tubing.
  • the container will be a vial or cuvette of some sterile substance such as glass or synthetic plastic of relatively stiff character. In other instances the container may have walls of flexible material.
  • a small wedge device is used to apply a laterial strain to the lower end of the length of tubing to cause it to break off below the level of the liquid in the container.
  • the user grasps the length of tubing through the walls between his fingers, on opposite sides of the score line and applies the lateral strain to sever the end from the longer length.
  • FIG. 1 is a fragmentary sectional view through a length of capillary tubing installed on a wedge device, shown on an exaggerated scale.
  • FIG. 2 is a sectional view showing the manner in which the end section of the length of capillary tubing is broken off by pushing down on the length of tubing.
  • FIG. 3 is a sectional view taken on the line 3-3 of FIG. 1 and in the direction indicated.
  • FIG. 4 is a sectional view similar to that of FIG. 2 but illustrating a wedge device of modified form which is operated by causing relative movement between the flexible end of the wedging device and the fixed end of the length of tubing.
  • FIGS. 5 and 6 are diagrammatic perspective views showing two steps in the method of practicing the invention using a container with flexible walls.
  • the method of the invention comprises disposing the scored end of an evacuated length of capillary tubing immersed in a liquid which it is desired to draw into the length of tubing and breaking the scored end from the longer length so that the liquid immediately is sucked into the bore of the longer length.
  • the container or cuvette is formed of some relatively stiff material, such as glass, methacrylate resins, and the like and in such cases a wedge device is used to achieve the application of lateral strain on the end of the length of tubing.
  • the container is in the form of a cuvette having walls which are flexible, somewhat like a bag. The liquid is in the container, the length is immersed in the liquid and the technician grasps the length of tubing between his fingers on opposite sides of the score line and manually breaks the tubing below the level of liquid.
  • the reference character 10 designates generally a length of capillary tubing of glass having a bore of uniform, accurately known diameter and which it is desired to fill with a liquid 12 contained in a suitable vessel 14.
  • the vessel in this case is made of glass or some stiff plastic, as common in the fields of biology, chemistry, hematology and the like.
  • the length of tubing 10 has its ends sealed as by flame sealing as shown at 16 and 18, and when sealed, the hollow bore 20 is evacuated. Just above the lower end 18 as viewed in the drawings, the length of tubing is scored to provide a score line shown at 22, the section between the score line 22 and the end 18 being designated the end section 24.
  • the techniques for flame sealing the ends in vacuum are well-known, and likewise the techniques for scoring are known. In furnishing the lengths of evacuated tubing, the maker may prescore them or leave the user to apply the score line 22 at any desired location.
  • a wedge device 26 When it is desired to fill the length of tubing 10 with the liquid 12, a wedge device 26 is fitted over the lower portion of the length 10.
  • the wedge device in FIGS. 1, 2 and 3 comprises a lower block 28 having a slanted or wedge surface 30 and an integral collar 32 providing an interior cylindrical passageway 34.
  • the axis of this passageway intersects the wedge surface 30 at an acute angle and obviously, when the length of tubing 10 is engaged in the passageway as described, it will be coaxial with the passageway 34.
  • the wedge device 26 is preferably made out of molded synthetic resin of some suitable type which is compatible with the liquid 12 and which provides a fair degree of firmness. There are many known plastics which are capable of being used, such as nylon, polyethylene, tetrafluorethylene, etc.
  • the diameter of the passageway 34 is chosen to fit firmly upon the length of tubing but to enable sliding thereof relative to the collar 32 when forced to do so.
  • the neck 36 between the collar and the block 28 in this case should be robust enough to resist substantial bending for a reason presently to be explained.
  • the wedge device 26 After the wedge device 26 has been fitted u on the length of tubing 10, it is immersed into the test fluid 12, the length of tubing 10 being pushed downward by the technician using either a small gripping sleeve or his fingers. This causes the length of tubing to slide through the passageway 34 of the collar 32. In the process of this movement, the end 18 moves against the slanted surface 30 and is deflected thereby, applying a lateral strain on the end 18.
  • the collar 32 holds the length of tubing 10 above the score line 22, and the strain is applied below the score line 22 as the length 10 is pushed downward. This lateral strain breaks the end section 24 at the score line 22, and this severed section drops to the bottom of the vessel 14. As soon as the break occurs, the vacuum in the hollow bore 20 draws a quantity of the liquid 12 into such bore and fills the same as shown at 12 in FIG. 2.
  • the length of tubing 10 is withdrawn from the liquid 12 carrying the wedge device 26 with it.
  • the wedge device 26 is now discarded and the length of tubing 10 with the occluded liquid 12 may be processed further as disclosed in the co-pending applications, as by dividing the same into shorter sections of known length and hence known volume for use as micro-samples.
  • FIG. 4 illustrates a modified form of the apparatus of the invention, also for use with a container that is relatively stifl.
  • the container 14' is a relatively shallow cuvette containing a small quantity of sample liquid 12 and the length of tubing 10 is scored at 22 above the end 18 as in the previously described structure.
  • the wedge device 26 in this instance is made of somewhat more flexible material than the device 26 previously described. For example, it could be an elastomer of some type which enables the two functions which provide the lateral strain for breaking off the end section 24.
  • the collar or handle portion 32 in this form of the apparatus is somewhat elongate so that it is capable of being grasped between the fingers of the technician as shown in FIG. 4.
  • the length of tubing is inserted into the passageway 34' and pushed down against the lower block portion 28' which may have a small seat or depression 29 molded into its slanted or wedge surface 30'.
  • the neck 36' is intentionally narrow and flexible so that when the entire wedge device 26' is pushed downward against the bottom wall of the vessel 14', the block portion 28 will swing to the broken line position shown in FIG. 4. This will apply the lateral strain required to break the end section 24 from the length of tubing.
  • the softness of the material from which the device 26' is molded enables the technician to pinch the handle portion 32' and thereby tightly grip the length of tubing 10 in the passageway 34' so that when the device 26' is pushed downward, there is no relative movement between the length of tubing 10 and the device 26.
  • FIGS. 1, 2 and 3 on the one hand, and the structure of FIG. 4 on the other hand is the movement of the length of tubing relative to the wedge device and fixation of the block and its wedge surface in the one case, and the fixation of the length of tubing and movement of the block and its wedge surface in the other case.
  • FIGS. and 6 there is illustrated an application of the method of the invention to a type'of container which has flexible side walls.
  • the container 50 in this case has a cover member or cap '52 of some relatively stiff material, such as synthetic resin of apolymerized type.
  • the body of the container 50 is a flexible bag 54 and the walls are preferably transparent.
  • bag 50* may be formed of polyethylene or the like.
  • the bag is sealed or thermally welded to the cap 52 and a passageway 56 in the cap enables the technician to insert the lower end of the length of tubing 10 into the interior of the container 50.
  • the bottom end of the passageway 56 may have a flapper valve (not shown) which prevents the liquid 12 in the bag from being contaminated until it is ready to be used.
  • the entrance to the passageway 56 may have a pair of closed abutting lips or flaps which may be envaginated by the insertion of the lower end of the length of tubing 10.
  • the technician holds the cap 52 in one hand as shown in FIG. 5 and inserts the length of tubing 10 with the other hand.
  • the length of tubing 10 When the length of tubing 10 is disposed with a substantial portion of its lower part within the bag it will be self-supporting long enough for the technician to move his hand from the upper end of the length to the lower end as shown in FIG. 6-, this lower end now being grasped through the flexible walls.
  • the very bottom tip, which is identified as 18 is that which is grasped by the right hand as shown in the views. This is below the score line 22. Now the technician can shift his left hand and, cradling the majority of the containers in his cupped hand, with his thumb and one of his forefingers he grasps the length of tubing through the flexible walls above the scored line.
  • the technician simply applies the lateral strain needed to break the lower section 24 free below the level of the liquid 12 to cause a quantity to be drawn into the bore of the length of tubing 10.
  • the broken piece 24 will remain in the bottom of the container, and other lengths may be filled in the same way after removal of the respective filled ones.
  • the construction of the vessel 50 is not intended to be limiting, but merely to illustrate one type of flexible wall vessel that will enable the lateral strain to be applied manually and without contamination of the sample by the technician or vice versa.
  • a method of filling a single length of sealed-end evacuated accurately sized bore capillary tubing with a sample liquid and retaining such fluid in the length which comprises:
  • a method of filling a single length of sealed-end evacuated accurately sized bore capillary tubing with a sample liquid and retaining such fluid in the length which comprises:
  • Apparatus for sampling fluid contained in a vessel which comprises:
  • a break-off member consisting of (i) means for supporting said length circumferentially at a location spaced axially from said score line but opposite to said one sealed end relative to the score line,
  • the supporting means and surface being spaced apart a suflicient distance such that the portion of said length of tubing between said score line and one sealed end will be broken away from said length of tubing by said lateral strain while said score line is immersed in said fluid.
  • break-off member is formed of an elastomeric material to enable the supporting means to be compressed for pinching the length of tubing through said supporting means.

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  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Pathology (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Immunology (AREA)
  • Physics & Mathematics (AREA)
  • Clinical Laboratory Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Sampling And Sample Adjustment (AREA)
  • Investigating Or Analysing Biological Materials (AREA)
  • Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
  • Devices For Use In Laboratory Experiments (AREA)
US849371A 1969-08-12 1969-08-12 Method and apparatus for filling a capillary tube with liquid Expired - Lifetime US3626762A (en)

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US84937169A 1969-08-12 1969-08-12

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US (1) US3626762A (ja)
JP (1) JPS4924704B1 (ja)
CA (1) CA929900A (ja)
CH (1) CH526100A (ja)
DE (1) DE2039000B2 (ja)
FR (1) FR2056615A5 (ja)
GB (1) GB1318285A (ja)
NL (1) NL7011553A (ja)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3779083A (en) * 1971-05-28 1973-12-18 Becton Dickinson Co Method and apparatus for measuring precise micro quantities of fluid samples
US4392497A (en) * 1980-12-02 1983-07-12 Ghaussy Rahmat U Erythrocyte sedimentation rate apparatus and method
US4528160A (en) * 1983-06-14 1985-07-09 Dragerwerk Aktiengesellschaft Gas dosimeter construction
US4539180A (en) * 1980-09-24 1985-09-03 Regents Of The University Of Minnesota Apparatus for quantitatively determining the level of hemoglobin in a biological sample
US5594183A (en) * 1993-07-28 1997-01-14 Bio Merieux Process for metering, in particular microvolumes of a liquid; application to obtaining controlled dilutions, especially nanomolar dilutions
EP1749421A2 (en) * 2004-03-05 2007-02-07 Peter E. Rising Liquid sampling apparatus and method of using same

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3779083A (en) * 1971-05-28 1973-12-18 Becton Dickinson Co Method and apparatus for measuring precise micro quantities of fluid samples
US4539180A (en) * 1980-09-24 1985-09-03 Regents Of The University Of Minnesota Apparatus for quantitatively determining the level of hemoglobin in a biological sample
US4392497A (en) * 1980-12-02 1983-07-12 Ghaussy Rahmat U Erythrocyte sedimentation rate apparatus and method
US4528160A (en) * 1983-06-14 1985-07-09 Dragerwerk Aktiengesellschaft Gas dosimeter construction
US5594183A (en) * 1993-07-28 1997-01-14 Bio Merieux Process for metering, in particular microvolumes of a liquid; application to obtaining controlled dilutions, especially nanomolar dilutions
EP1749421A2 (en) * 2004-03-05 2007-02-07 Peter E. Rising Liquid sampling apparatus and method of using same
EP1749421A4 (en) * 2004-03-05 2010-06-16 Peter E Rising LIQUID SAMPLING DEVICE AND THESE USE PROCEDURES

Also Published As

Publication number Publication date
CA929900A (en) 1973-07-10
DE2039000A1 (de) 1971-02-25
CH526100A (fr) 1972-07-31
NL7011553A (ja) 1971-02-16
FR2056615A5 (ja) 1971-05-14
GB1318285A (en) 1973-05-23
DE2039000B2 (de) 1976-01-29
JPS4924704B1 (ja) 1974-06-25

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