JP2002001136A - Nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nozzle which decreases the carryovers of a suction and discharge nozzle of an automatic analyzer for sampled and reagents and above all an automatic analyzer for clinical testing and makes exact and precise measurement possible. SOLUTION: The nozzle which decreases the carryovers of the suction and discharge nozzle for samples and reagents and makes the exact and precise measurement possible is provided by providing the nozzle with one or >=2 features selected from at least the following (1) to (3); (1) The nozzle has linear and spiral projecting structures on its inner wall, (2) the front end on the suction and discharge side of liquid has a C-shaped structure and (3) the nozzle has four projecting parts on the inner wall side in the front end area of the suction and discharge side of liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for an automatic analyzer, particularly a nozzle for aspirating and discharging a sample or a reagent of an automatic analyzer for clinical examination.

[0002]

2. Description of the Related Art Various nozzles used for dispensing samples and reagents when quantifying chemical components in biological samples such as plasma and serum have been proposed. Factors that determine the accuracy and reproducibility of the dispensed amount of the nozzle include the fact that the set amount is accurately sucked into the nozzle, whether the sucked liquid is correctly discharged, and the outer wall of the nozzle. Another important factor is how much liquid to be dispensed adheres to the inner wall and is carried into the next sample or reagent (also called carryover). In particular, when performing multi-pipetting in which a plurality of samples or reagents are suctioned and discharged by the same nozzle, it is necessary to reduce the amount of liquid adhering to the outer wall of the nozzle in order to reduce carryover.

[0003] Reducing carryover is extremely important in assessing nozzle performance because it is associated with contamination problems, as well as in dispensing accurate amounts of sample.

[0004] A nozzle for aspirating and discharging a sample or a reagent of a general automatic analyzer, especially an automatic analyzer for clinical examination, is a metal or plastic molded product, and the nozzle having a smooth inner wall is used. , With a nozzle with a smooth structure, after discharging the sucked sample or reagent,
When the inside of the nozzle is cleaned with the cleaning liquid supplied from the upper part of the nozzle, there is a disadvantage that the cleaning liquid does not spread over the entire inner wall and cleaning failure occurs. Therefore, there are problems in operation and handling, such as a large amount of a cleaning solution is required.

Japanese Patent Application Laid-Open No. 63-23749 discloses a method in which a taper-like tapered surface is formed on the outer peripheral surface at the foremost portion of a nozzle to improve liquid drainage and reduce the amount of liquid adhering to the outer wall of the nozzle. , Reducing carryover. Japanese Patent Application Laid-Open No. 5-168954 discloses that the shape calculated from the surface tension of the liquid, the mass density of the liquid, and the like is used at the tip of the nozzle to improve the liquid shortage and reduce the amount of the liquid adhering to the outer wall of the nozzle. Techniques for reducing this are disclosed. Further, Japanese Patent Application Laid-Open No. HEI 8-112737 discloses that the tip of the nozzle on the liquid suction / discharge port side has a curved shape toward the tip and the wall thickness of the nozzle is set to the liquid suction / discharge port side. By gradually thinning as you go,
There is disclosed a technology of a nozzle having good dispensing performance, in which the outer wall surface has a good drainage of liquid and little adhesion of liquid to the outer wall surface.
However, these techniques alone do not provide satisfactory dispensing accuracy.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to clean the inside of a nozzle with a cleaning liquid supplied from the upper part of the nozzle after discharging the sucked sample or reagent, and the cleaning liquid does not spread over the entire inner wall, causing a cleaning defect. It is an object of the present invention to provide a nozzle that solves the above drawbacks. It is a further object of the present invention to provide a nozzle capable of improving the accuracy of dispensing a sample or reagent sucked.

[0007]

[Means for Solving] As a result of intensive studies, the present inventors have found that
After discharging a sample or a reagent sucked by a nozzle having a concave and / or convex structure on at least a part of the inner wall surface, the inside of the nozzle is cleaned with a cleaning liquid supplied from an upper portion of the nozzle, so that the cleaning liquid does not spread over the entire inner wall. Can solve the drawback of causing poor cleaning. The concave and / or convex structures may be linear or band-shaped. The optimum conditions for the position, length and shape can be determined by repeating simple experiments. FIG. 1 shows a diagram of a nozzle having a linear and spiral convex structure on the inner wall of the nozzle.

In addition, the end of the outer wall on the liquid suction / discharge port side has a shape formed by two or more discontinuous straight lines, that is, a C-shaped structure. For this reason, the liquid adhering to the outer wall of the nozzle drops quickly without collecting at the corner of the nozzle tip, and the liquid runs out better, so that the adhesion of the liquid to the outer wall can be reduced and the dispensing performance can be improved. Will be possible. FIG. 2 shows a tip view of the nozzle having the C structure.

[0009] Further, the structure having at least two convex and / or concave portions on the inner wall side at the distal end portion on the liquid suction / discharge port side allows the arm of the automatic analyzer to move in the horizontal direction while the sample or reagent is being suctioned. It has been found that the liquid can be prevented from falling and splashing even when the liquid is moved to the discharge position, and the discharge accuracy can be improved. More specifically, a convex structure is preferable, and the number is preferably 1 to 20, more preferably 2, 4 or 8 convex structures. FIG. 3 shows a tip view of a nozzle having four convex structures.

According to the present invention, at least a part of the inner wall surface of the nozzle has a helical convex and / or concave structure, and / or a C-shaped structure in which the tip on the liquid suction / discharge port side faces the tip. And / or suction /
The present invention relates to a nozzle having preferably four convex structures on the inner wall side of the tip portion on the discharge port side. The nozzle of the present invention is exemplified by a metal or plastic molded product, but the material is not particularly limited. Further, the nozzle of the present invention may have a function of being detachable from the pipette body.

The nozzle of the present invention has a convex and / or concave position on at least a part of the inner wall surface to discharge the sucked sample or reagent, and then cleans the inside of the nozzle with the cleaning liquid supplied from the upper portion of the nozzle. At this time, the cleaning liquid spreads over the entire inner wall, and the cleaning effect of the nozzle can be significantly improved. Further, the nozzle of the present invention has a shape in which the tip on the liquid suction / discharge port side is formed by two or more discontinuous straight lines, that is, a C-shaped structure. For this reason, the liquid adhering to the outer wall of the nozzle drops quickly without collecting at the corner of the nozzle tip, and the liquid runs out better, so that the adhesion of the liquid to the outer wall can be reduced and the dispensing performance can be improved. Will be possible. Further, the nozzle of the present invention has two or more convex portions on the inner wall side at the tip portion on the liquid suction / discharge port side.
For this reason, even when the sample or the reagent is horizontally moved to the discharge position while being suctioned, the liquid does not drop or scatter, and the dispensing performance can be improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be further described below with reference to the drawings, but the present invention is not limited to the embodiments.

[0013]

FIG. 1 is a view of one embodiment of a nozzle according to the present invention. In FIG. 1, a nozzle according to the present invention has an inverted conical cylindrical body 1 made of a synthetic resin material such as polypropylene.
Liquid suction / discharge small hole 2 and connection area 3 with pipette device
Are formed. A spiral convex structure 4 is provided on the inner wall surface.
Are formed.

[0014]

Embodiment 2 FIG. 2 is an enlarged view of a tip portion of a nozzle according to the present invention. FIG. 2 shows an example of a nozzle in which the tip portion of the nozzle has a C-shaped structure. In the shape up to the outside of the tip and the small hole for sucking and discharging the sample,
A notch 6 is formed in a straight line at an obtuse angle at the outside discontinuous point portion of the flat portion, and a portion connected to the flat portion discontinuous point portion 7 at an obtuse angle is formed, leaving a part of the flat surface at the tip. I have.

[0015]

Embodiment 3 FIG. 3 is an enlarged view of a tip portion of a nozzle according to the present invention. FIG. 3 shows an example of a nozzle in which the tip portion of the nozzle has a triangular convex portion on the inner wall side. That is, a triangular projection is provided toward the center of the small hole for suction and discharge.

[0016]

Embodiment 4 An embodiment of a nozzle for collecting a sample amount of about 10 to 300 μl will be described below. As shown in FIG. 1, a spiral convex portion is provided on the body of the nozzle. The number of spirals is not limited, but it is effective to arrange two linear convex structures in a spiral. As shown in FIG. 2, the outer wall of the tip has a C-shaped structure, and the inner wall has a structure shown in FIGS. 3 (a) and 3 (b).
As described above, four projections are provided toward the center of the small hole for suction and discharge. The nozzle is an inverted conical cylindrical body 1 made of a synthetic resin material such as polypropylene,
Liquid suction / discharge small hole 2 and connection area 3 with pipette device
Are formed. Examples of the most preferable shape of the nozzle include a liquid suction / discharge side tip diameter of 0.8 to 2.0 mm,
The diameter of the liquid suction / discharge small hole 2 is 0.4 to 0.6 mm, and the wall thickness of the liquid suction / discharge side tip is 0.1 to 0.4 mm. In this case, one of the preferable examples is that the wall thickness on the side of the connection area 3 with the pipette device is 0.3 to 1.0 mm. As a result of such an improvement, the nozzle of the present invention has a liquid attachment amount to the outer wall surface at the liquid suction / discharge-side tip end portion which is 1/2 to 1/10 as compared with other types of nozzles.

The above example is a nozzle used for dispensing a sample amount of about 10 to 300 μl, and is not limited to this, and other applications are also possible. Further, the present invention is applicable not only to disposable nozzles used in automatic analyzers and the like but also to use by connecting to a suction device such as a handy type pipettor. In addition, as described above, the nozzle of the present invention can reduce the amount of liquid adhering to the outer wall surface of the liquid suction / discharge-side tip portion as compared with other types of nozzles. It is effective for a method / apparatus using a multi-pipetting method for aspirating / discharging or dispensing a plurality of reagents or samples. One embodiment of performing multi-pipetting using the present invention will be briefly described below, using a reaction system for quantifying a chemical component in a biological sample such as serum. A necessary amount of the reagent A is aspirated by a pipette connected to the nozzle of the present invention. Thereafter, the aspirated reagent is discharged into the reaction vessel and allowed to react, and a target chemical component is quantified. Next, before a different reagent B is similarly suctioned and discharged, the nozzle is washed with a cleaning liquid or the like, and the reagent B is suctioned and discharged to react.

[0018]

According to the present invention, multi-pipetting which has high nozzle cleaning efficiency and good dispensing performance, and performs suction / discharge and dispensing of a plurality of reagents and samples with one nozzle. It has become possible to easily provide an effective nozzle for the method / apparatus using the method.

[Brief description of the drawings]

FIG. 1 is a view of a nozzle having two spiral convex structures on a pair of inner walls. (A) is a view from the front (b) is a view from the right side of (a) (c) is a cross-sectional view of (b)

FIG. 2 is an enlarged view of a nozzle having a C-shaped structure at a tip portion on a liquid suction / discharge port side.

FIG. 3 is an enlarged view of a nozzle having four protrusions on an inner wall side at a tip end on a liquid suction / discharge port side. (A) is a view of the nozzle tip viewed from the liquid suction / discharge port side. (B) is a sectional view of (a) and is an enlarged view of a front end portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inverted conical cylindrical body, 2 ... Small hole for liquid suction / discharge, 3 ... Connection area with pipette device, 4 ... Helical convex part, 5 ... Outside discontinuous point part, 6 ... Notch part, 7 ... Flat part discontinuity point,
8 Projection site

Claims (7)

[Claims] 1. A nozzle for sucking and discharging a liquid sample, the nozzle having at least one or two or more characteristics selected from the following (1) to (3). (1) At least a part of the inner wall surface has a concave and / or convex structure. (2) The tip of the outer wall on the liquid suction / discharge port side is at least 2
Shapes with point discontinuities. (3) A shape having a convex portion and / or a concave portion on the inner wall side at the tip portion on the liquid suction / discharge port side. 2. A nozzle having a helical convex and / or concave structure on at least a part of an inner wall surface. 3. A nozzle having a C-shaped structure at the tip of the liquid suction / discharge port side. 4. A nozzle having 3 to 8 convex portions on the inner wall side at the tip end portion on the liquid suction / discharge port side. 5. The nozzle according to claim 1, wherein the nozzle is a metal or plastic molded product. 6. The nozzle according to claim 1, which is detachable. 7. A nozzle according to claim 1, wherein the nozzle is a nozzle for sucking and discharging a sample or a reagent.