JPH01297175A - Water-repellent treatment of pipe nearby its tip end - Google Patents

Abstract

PURPOSE:To avoid to bring about errors 1n quantity of liquid dropping from a pipe by bringing an outer face nearby an end of the pipe into contact with faces of two members, which hold a liquid giving water-repellency to a hydrophilic surface, so as to form a water-repellent surface on the outer face of the pipe. CONSTITUTION:A water-repellent surface is formed on an outer face nearby an end of a pipe 7, e.g., a nozzle tip of a micropipet, by inserting downward the pipe 7 into a hole of a pipe holder 8, wherein liquid holding members 3 and 3' impregnated with a proper amount of a commercial silicone liquid is arranged, and by making the silicone oil adhere to the outer face nearby the tip end of the pipe 7. When a definite amount of liquid is discharged once or repeatedly from an open end of the pipe 7 such as the nozzle of the pipet used for analysis, a positive or negative error in an amount of liquid dropping from the pipe 7 does not occur, because a part of the liquid does not adhere to the outer face nearby the tip end of the pipe 7. It is possible, as a result, to improve an accuracy in a quantitative analysis of a component in a liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for making a surface such as a tip of a tube water repellent, and an apparatus used to carry out the method.

In particular, the present invention relates to a method and apparatus useful for forming a water-repellent surface near the tip of a nozzle (discharge tube) of a metering pipette for supplying a fixed amount of sample liquid in chemical analysis.

[Prior Art] Recently, dry method clinical chemistry tests have come into widespread use because they are superior in terms of simplicity of analysis work, rapidity of measurement, and the like. In clinical chemistry testing using this dry method, a liquid sample is spotted on a chemical analysis slide containing a reagent that reacts with specific components such as glucose and urea nitrogen (BUN) in a liquid sample such as blood. Specific components are quantified by colorimetric analysis of color development, discoloration, etc. caused by the reaction of specific components.

Conventionally, in order to apply a specimen (sample solution) onto a chemical analysis slide, a predetermined amount of the specimen is inhaled using a pipette, and then a round droplet of the specimen is formed at the tip of the pipette, and this droplet is then applied to the chemical analysis slide. It was applied by gently touching the center of the analysis slide.

In this method of spotting a specimen, there are large individual differences in spotting accuracy, making it difficult to obtain satisfactory t91 test accuracy. The main causes of this individual difference are that it is difficult to maintain a constant relative position between the tip of the pipette (nozzle) and the spotting surface of the chemical analysis slide, and that Droplets often did not form unless the adhering liquid was wiped off.

To eliminate individual differences in spotting, attach the pipette to a stand,
One good method is to force the liquid out of the pipette manually or dynamically. However, in this case, Bibetsu 1
Since the distance between the tip of the pipette and the spotting surface of the chemical analysis slide is constant, it is not possible to form a droplet at the tip of the pipette nozzle and then bring it into contact with the chemical analysis slide and deposit it.

There are a variety of sample liquids tested on chemical analysis slides, such as whole blood, plasma, serum, their diluted solutions, urine, and saliva, which have different viscosities. ) are absorbed at different rates. Furthermore, different types of analysis slides are used depending on the component to be detected, and even for the same type of sample liquid, the speed at which it is absorbed into each surface of the liquid receiver (usually the developing layer) depends on the type of chemical analysis slide. If the speed at which the droplet is ejected from the bed is too fast compared to the speed at which it is absorbed into the chemical analysis slide, some of the droplets will adhere to the area around the nozzle tip and remain there, causing an error in the amount of liquid deposited. . That is, the supply liquid 1 is insufficient in the spotting that caused the adhesion, and in the subsequent spotting, the previously deposited liquid is combined, resulting in a positive (+) error in the liquid amount.

In order to prevent droplets from adhering to the surface of the tube near the tip of the nozzle, it was also considered to construct only the outside of the nozzle with a water-repellent material. This structure complicates the nozzle manufacturing process and increases cost.

Moreover, it is time-consuming to wipe off the liquid adhering to the outside of the tip of the nozzle every time liquid is sucked, and if you are not careful enough, you may forget to wipe it off, resulting in an error in the amount of liquid.

[Technical Problems to be Solved] The present invention provides a method for discharging a certain amount of liquid from the tip of an open tube such as a nozzle (discharge tube) of a pipette used in analysis - times or repeatedly. An object of the present invention is to provide a method for forming a water-repellent surface on an outer surface near the tip of a tube in order to prevent a portion of liquid from adhering to the outside near the tip of the tube, and an apparatus for carrying out the method.

The present invention also provides a solution to the outside of the nozzle of the metering pipette so that a sample solution can be dropped once or repeatedly in a high volume interval without some of the liquid adhering to the outside of the tube near the tip. A technical problem is to provide a method for forming a water-repellent surface on a surface [Means for solving the technical problem] One of the above-mentioned problems of the present invention is to provide a method for forming a water-repellent surface on a surface of two members having liquid-retaining surfaces. A liquid having a property of imparting water repellency is retained on the liquid-retaining surface, and the vicinity of the tip of the tube is brought into contact with the liquid-retaining surface of the two members to form a water-repellent surface on the outer surface near the tip of the tube. Solved by the method of forming.

Another object of the present invention is to provide two members having a liquid-retaining surface and retaining a liquid having a property of imparting water repellency to the liquid-retaining surface, and a pipe. means for holding the tube such that the tube rotates between these two surfaces while simultaneously bringing the vicinity of the tip of the tube into contact with the liquid-retaining surfaces of the two members; and means for moving said two members so as to move in opposite directions along a surface.

The pipe to be subjected to water-based treatment in the present invention may have an oval, polygonal, etc. cross section, but is preferably circular.
The outer diameter of the tube to be treated (e.g. the nozzle of a pipette) may be constant or variable along its length, but it is preferable that the tube is a linear rotating body at least near the tip. If the diameter is constant, it is preferable to provide a liquid-retentive surface on the outer periphery of the cylinder, excluding the tip. If the tube has a truncated conical shape near the tip, the outer periphery of the truncated cone, excluding the tip, is preferable. It is preferable to provide a liquid-retaining surface on the part.

To provide a liquid-retaining surface on two members, cloth, felt, paper, nonwoven fabric, string, thread, etc. may be wrapped or attached to the outer surfaces of the members. It is preferable that the liquid-retaining member is soft. This is because when the tip of the tube comes into contact with the tube, it is slightly depressed and comes into contact with a relatively wide area of the outer periphery of the tube.The entirety of the nine members or the portions other than the center may be made of a liquid-retaining material.

When carrying out the method of the present invention, it is preferable to bring the vicinity of the tip of the tube into contact with the liquid-retentive surfaces of the two members at the same time, and rotate the tube between the two surfaces. The surfaces may both be flat, or both may be cylindrical surfaces or parts of cylindrical surfaces.The liquid-retaining surface of one of the two members is flat, and the liquid-retaining surface of the other member is flat. The object may be a cylindrical surface or a part of a cylindrical surface.

If the two members have liquid-retaining planes that can move parallel to each other in opposite directions, it is convenient to rotate the vicinity of the tip of the tube between those planes.For example, the two members: If the plate member has liquid-retaining flat surfaces on opposing surfaces, by moving them parallel to each other in opposite directions, it is possible to rotate the tube with the tip of the tube sandwiched between the two flat surfaces. , which is convenient.

When the two members are cylindrical or cylindrical, by rotating them in the same direction, it is convenient to sandwich the tip of the tube between their outer peripheral surfaces and rotate the tube.

As the water-repellent liquid used to form a water-repellent surface near the tip of the tube, silicone oil, which is widely used as an anti-water treatment agent, is suitable in terms of availability, price, etc. However, it is also possible to select from among vegetable oils, animal oils, mineral oils, synthetic esters, higher alcohols, etc., those that can adhere to the outer peripheral surface near the tip of the tube.1! It may also contain a solvent with appropriate volatility.

INDUSTRIAL APPLICABILITY The present invention is useful for anti-hydration treatment of the outer surface of the tip of a liquid injection nozzle of a pipette used for measuring sample liquids, reagents, etc. in clinical chemistry tests.

Pipettes used for dotting on chemical analysis slides in clinical chemistry tests often have a cylinder and a piston.The 6-bib pipette may have a fixed nozzle, or may be a removable or disposable nozzle. A nozzle tip may be used, for example, those described in US Pat. No. 4,072.330, US Pat. No. 4,237,095, and US Pat. Many commercially available nozzle tips are made of polypropylene from the viewpoint of processing accuracy.

The outer diameter of the tip of the pipette nozzle is usually about 0.3 mm to 1.51 mm. Preferably it is from 0.5 mm to 1.21 mm.

Although the present invention is not limited in its application by the outer diameter of the tube, it is useful in cases where droplets are formed on the outer surface of the tube, and has no practical effect on tubes with an outer diameter exceeding 5 Ml11. It will be difficult to obtain.

When applied to pipettes etc. with removable nozzles,
The length of the nozzle is 1 (there is no particular limit, but the nozzle must be long enough to be held when carrying out the present invention. In the case of a disposable nozzle tip, etc.
The length of the nozzle is determined by the desired amount of liquid to be accommodated. In the case of a nozzle with an outer diameter of about 0.5 to 31, the range in which the outer surface near the tip is made water repellent by the present invention is:
Approximately 10mm from the tip is sufficient, 3 to 1.0+
The optimum value is about n+++. If it is made water-repellent further away from the tip, the effectiveness of preventing the liquid from flowing down along the outer surface will actually decrease.

[Effect of the invention] When the present invention is used, when a certain amount of liquid is discharged from the tip of an open tube such as a nozzle (discharge tube) of a pipette used in analysis - times or repeatedly, Since no part of the liquid adheres to the outside near the tip, there is no positive or negative error in the amount of liquid dripped from the tube.As a result,
For example, the accuracy of quantitative chemical analysis regarding components in a liquid can be improved. It is also possible to prevent the liquid adhering to the relatively upper outer surface from gradually flowing down and being added to the liquid being discharged (causing an error in the amount of dropped liquid).

The present invention is useful not only for pipettes but also for burettes and the like used for quantitative analysis. Furthermore, the present invention is useful not only in liquid measuring containers used in chemical analysis, but also in cases where it is important to consistently form droplets of a relatively constant size (e.g., during infusion, the number of droplets (when controlling the flow rate).

[Example 1] A device as shown in FIG. 1 was manufactured. In Figure 1,
1 is a support frame, 2 and 2'' are gutter-like members, 3 and 3' are liquid retaining members fixed to gutter-like members 2 and 2', respectively, and 4 and 4' are on the - edge of the gutter-like members. 5 is a rack that engages with the racks 4 and 4'', 6 and 6'' are springs that bias the plate members 2° and 2° in opposite directions, 7 is a pipe to be processed, and 8 is a The tube holding member 9 indicates a knob that moves the plate member 2 in the horizontal direction against the bias of the spring 6. The members 3'' are fixed to the surfaces sandwiched between the edges of the gutter-like member 2''.The liquid retaining members 3 and 3'
can be in contact with the tube 7 held by the tube holding member. The tube holding member 8 has a hole in the center for rotatably holding the tube 7 therethrough.

The liquid retaining members 3 and 3° are felt.

Fill the entire surface of the liquid holding member 3 and 3° with an appropriate amount of commercially available silicone oil, insert the tube 7 to be processed, for example, the nozzle depth of a micropipette, downward into the hole of the tube holding member 8, and press the knob 9 with your finger. Then, the gutter-like member 2 is moved to the right in the figure against the bias of the spring 6, and at the same time, the rack 4 is moved to the right in the figure, and the rack 4' is moved to the left in the figure via the pinion 5 that meshes with the rack 4. Moved. The trough 2°, which is integral with the rack 4', therefore moves in the opposite direction to the trough 2. This causes the tube 7 sandwiched between the trough-like members 2 and 2' to rotate clockwise.

Since the tip of the tube 7 rotates in contact with the liquid holding members 3 and 3', the surface where the tip of the tube 5 contacts the liquid holding members 3 and 3' extends over the entire circumference of the tube 7 during the rotation. i.e. tube 7
Silicone oil adheres to the entire circumference near the tip, forming a water-repellent surface. In this way, a water-repellent surface was formed on the outer surface near the tip of the tube 7.

[Example 2] A device as shown in FIG. 2 was manufactured. In Figure 2,
1 is an outer box that also serves as a substrate, 2 and 2' are cylindrical members, and 3
and 3' is a liquid holding member provided surrounding the cylindrical member; 4 and 4' are gears fixed to the cylindrical members 2 and 2', respectively; 5 is a rotating member that rotates around the shaft 5a;
6 is a group of gears for rotating the rotating member 5; 7 is a tube to be processed; 8 is a tube holding member; 8a is a fixed gear provided at one end of the tube holding member 8 and meshing with gears 4 and 4'; 9 indicates a motor. The cylindrical members 2 and 2' can rotate around axes 2a and 2a' fixed to the pivot member 5. The liquid retaining members 3 and 3° provided on the surfaces of the cylindrical members 2 and 2' can be in contact with the tube 7 held by the tube retaining member 8. The tube holding member 8 has a hole in the center for passing the tube 7 through and retaining bacteria, and is fixed to the outer box 1. The tube 7 is rotatably held by a holding member 8. The liquid holding member 3.3° is made of sponge (plastic foam) 6. The motor 9 is connected to a power source (not shown) via a switch (not shown).

With the motor 9 stopped, commercially available silicone oil is supplied to the liquid holding members 3 and 3', and the nozzle tip of the tube 7 to be processed, for example, a micro and bed, is inserted into the hole of the tube holding member 8, facing downward. Insert it into the

When the motor 9 is rotated, the rotating member 5 is rotated through the gear group 6.
rotates around the shaft 5a, and the gears 4 and 4' rotate around the shaft 2a while revolving around the gear 8a. tJi car 4
．． The cylindrical member 2゜2゛ to which 4゛ is fixed, and therefore the liquid holding members 3 and 3'' also undergo a similar rotational movement.The tip of the tube 7 is sandwiched between the liquid holding member 3 and 3°. Because it rotates,
The surface where the tip of the tube 7 contacts the liquid holding members 3 and 3' is
During the above rotation, silicone oil adheres to the entire circumference of the tube 7, that is, to the entire circumference near the tip of the tube 7, forming a water-repellent surface. In this way, a water-repellent surface was formed on the outer surface near the tip of the tube 7.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view in three directions showing how the device used in Example 1 of the present invention is used, FIG. 2 is a cross-sectional view showing the state of use of the device used in Example 2 of the present invention, and FIG. The figure is a schematic diagram showing the state of droplets formed on a nozzle chip treated by the method of the present invention, and Figure 4 shows droplets formed on a nozzle chip (prior art) that does not have a water-repellent surface formed on its outer periphery. It is a schematic diagram showing the state of. Applicant: Fuji Photo Film Co., Ltd. Figure 2 Figure 3 Hiraitonuchi 1] "Toy IT (Spontaneous) \V April 3, 1989 [1 1, 11 Displays 1988 Patent Application No. 126548 2 Invention Name of fhx processing near the tip of the tube 3, person making the correction Relationship with the JT case Patent applicant address Fujishako 1, 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture
Film Co., Ltd. Tokyo Head Office Tel: (406) 2537 4. Subject of amendment The description in the "Detailed Description of the Invention J" column 5 of the description and the "Detailed Description of the Invention" column of the description of the amendment will be amended as follows. After "may be." in the first line of page 10 of the specification, it is preferable that the silicone oil has a molecular weight of 5000-L or more. ” is inserted. that's all

Claims (1)

[Scope of Claims] 1) The liquid-retaining surfaces of two members having liquid-retaining surfaces retain a liquid having a property of imparting water repellency, and the liquid-retaining surfaces of the two members A method of forming a water-repellent surface on the outer surface near the tip of the tube by bringing the tip of the tube into contact with the tube. 2) Claim 1, wherein the liquid-retaining surface is flexible.
)the method of. 3) The method according to claim 1, wherein the vicinity of the tip of the tube is brought into contact with liquid-retaining surfaces of the two members at the same time, and the tube is rotated between the two surfaces. 4) The method according to claim 1), wherein both liquid-retaining surfaces of the two members are flat. 5) The method according to claim 1), wherein the liquid-retaining surface of one of the two members is a flat surface, and the liquid-retaining surface of the other member is a cylindrical surface or a part of a cylindrical surface. . 6) The method according to claim 1, wherein the liquid-retentive surfaces of the two members are cylindrical surfaces or portions of cylindrical surfaces. 7) The method of claim 1), wherein the two members are cylinders or cylinders. 8) Two members that hold a liquid that has a liquid-retaining surface and have a property of imparting water repellency to the liquid-retaining surface, and the liquid-retaining surface of the two members near the tip of the tube. means for holding the tube so that it rotates between the two surfaces while being simultaneously in contact with the surfaces of the two members; A device for forming a water-repellent surface on the outer surface of a tube near its tip, characterized in that it comprises means for moving two members. 9) The device according to claim 8, wherein the two members have liquid-retentive planes that are movable parallel to each other in opposite directions. 10) The device of claim 8), wherein the two members are rotatable cylinders or cylinders.