JP2002031595A - Manufacturing method of flow cell and flow cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute position adjustment and fixation of a micro-tube accurately and easily, when the micro-tube is used on a orifice part of a flow cell used for a particle analytical device or the like. SOLUTION: A circular cone part 7 of a jig 6 is inserted into a circular cone-shaped through hole 2 and brought into close contact therewith. Then, the micro-tube 5 is inserted into a cylindrical through hole 3 so as to be positioned coaxially with the jig 6, and the micro-tube 5 head is brought into contact with the jig 6. The circular cone part 7 of the jig 6 blocks a connection part between the circular cone-shaped through hole 2 and the cylindrical through hole 3, to thereby enable optimum position adjustment without projection of the micro-tube 5 head into the circular cone-shaped through hole 2, and without stay thereof into the cylindrical through hole 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a flow cell when a fine tube is used as a flow cell used in a particle analyzer or the like, and to the flow cell.

[0002]

2. Description of the Related Art In particle measurement in a sample test such as blood analysis or urine component analysis, a flow cytometry method is frequently used as a measuring method. In this method, a sample liquid (a suspension of particles) discharged from a nozzle is caused to flow around the sample liquid to narrow down the sample liquid in a sheath flow cell. Therefore, measurement or analysis of particles in the sample liquid can be performed by performing optical or electrical measurement. The “sheath flow” refers to a flow in which a suspended liquid of particles is narrowed to almost the outer diameter of the particles at the center of the sheath liquid flowing through the orifice in a laminar flow state, and the particles are accurately aligned in a line and passed therethrough. In the structure of the flow cell, a portion where the sheath liquid advances to create a laminar flow state of the sheath liquid and the suspended liquid of the particles flowing in the central part is called a “rectifying unit”, and the laminar flow is gradually narrowed down. The part that leads to the orifice while it is moving is called the "acceleration part", and the part that flows the particle suspension liquid in a finely squeezed state for performing optical or electrical measurement is called the "orifice part".

[0003] In recent laboratory tests, not only in a laboratory or a test center in a hospital, but also in the vicinity of a patient (so-called point of care (POC)), importance has been placed on the POC field test apparatus. It is required to be inexpensive along with small size, light weight and operability. However, conventional flow cells were very expensive. The reason is that the inner wall of the flow cell needs to be as smooth as possible to ensure a stable laminar flow of the sheath liquid and the sample liquid, but it requires a great deal of skill to manufacture the flow cell by cutting. did. Also, the production of the orifice portion requires a very troublesome process such as bonding and welding several pieces of glass. Furthermore,
When forming the orifice part and the acceleration part separately and bonding them together, in addition to precision cutting, they have been integrally formed using a method of mutually welding with heat or chemicals. That is, the manufacturing cost of the conventional flow cell is inevitably increased due to the difficulty of manufacturing and the required high processing accuracy.

[0004] An apparatus using such a flow cell is not suitable for a POC field inspection apparatus in terms of manufacturing cost.
Therefore, in order to reduce the cost of the flow cell, development of a flow cell using an inexpensive microtube in the orifice portion has been promoted.

[0005]

The conventional flow cell in which the rectifying section, the accelerating section, and the orifice section are integrally formed is expensive, but the setting at the time of use is relatively easy. On the other hand, when an inexpensive microtube is used for the orifice portion, a problem described below with reference to FIGS. 1 and 2 occurs. That is, the holding portion 1 (the “holding portion” in the present invention refers to a conical through-hole serving as an acceleration portion, and a cylindrical through-hole for holding and connecting a fine tube to the tip of the conical through-hole. It is necessary to join the micro tube 5 serving as an orifice portion. If the micro tube 5 is protruded into the accelerating part 2 even if it is slightly protruded (FIG. 1), the sample The laminar flow of the liquid may be disrupted, resulting in inaccurate particle measurement. When the micro tube 5 is joined without reaching the conical through hole 2 (FIG. 2), a step occurs between the accelerating portion (conical through hole 2) and the orifice portion (micro tube 5). Also, the laminar flow of the sample liquid may be disturbed, and the accuracy of particle measurement may be lost.

[0006] In view of the above problems, a method of manufacturing a flow cell which can accurately and easily adjust and fix the position of a microtube and a holding portion, and a flow cell manufactured by the method are provided. That is the object of the present invention.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a fine tube, a holding portion having a conical through hole connected to an end of the fine tube, and a holding portion having a conical through hole. And a jig having a conical portion having a tapered angle to make the conical through hole and the conical portion of the jig in close contact with each other. A second step of arranging the fine tube on the same axis of the tool and bringing the end of the fine tube into contact with the conical portion of the jig; and a third step of bonding the fine tube and the holding portion. And a flow cell manufactured by the method. According to the present invention, accurate and easy position adjustment and fixation of the fine tube and the holding portion can be performed, and the production of a flow cell using an inexpensive fine tube for the orifice portion is realized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings. The scope of the present invention is not limited by the present embodiment.

In FIG. 3, a holding section 1 having a conical through-hole 2 and a cylindrical through-hole 3 is integrally formed with a rectifying section 4 having a cylindrical through-hole. And as shown in FIG.
The flow cell is constituted as a whole by connecting the cylindrical through-hole 3 and the fine tube 5. The material of the holding portion is not particularly limited as long as the surface of the internal through-hole is smooth and has physical and chemical resistance not to be affected by the passing liquid. For example, stainless steel, inorganic glass, vinyl chloride resin, acrylic resin and the like can be mentioned. The material of the holding portion in this embodiment is a vinyl chloride resin, and the dimensions of each portion in FIG. 3 are as follows. A (rectifying portion diameter) = 5 mm B (rectifying portion length) = 46 mm C (conical through hole length) = 5 mm Conical through hole taper angle = 50 degrees D (cylindrical through hole length) = 5 mm

[0010] The material of the fine tube serving as the orifice portion is not particularly limited as long as the surface of the internal hole is smooth and has physical and chemical resistance not to be affected by the passing liquid.

In particular, in the case of performing an optical measurement, light for particle measurement is irradiated to obtain forward scattered light and side scattered light. Any material may be used as long as it is transparent and has physical and chemical resistance that is not affected by the passing liquid. For example, inorganic glass, vinyl chloride resin, acrylic resin and the like can be used. Further, it is preferable that the section to be irradiated with light is formed of a square or rectangular prism.

In this embodiment on the premise of optical measurement, Poly
Micro Technologies WWP100375 (material is inorganic glass, cross-sectional shape is square at both outer edge and inner hole) was used.
This has a polyimide coating on the surface, so the coating must be removed before use. The coating can be easily removed by a method such as oven treatment, heat treatment such as spark discharge, and chemical treatment with sulfuric acid. FIG. 5 is a cross-sectional view of the fine tube used in this example. The cross-sectional shapes of both the outer edge and the inner hole are square. One side of the square of the outer edge section is 30
0 μm (at the time of coating removal), one side of the square of the cross section of the internal hole is 100 μm.

FIG. 6 shows an example of a jig. The jig 6 has a shape having a cone at the tip of a cylinder. The conical portion 7 has a taper angle (50 degrees in the present embodiment) in close contact with the conical through hole 2. The diameter of the jig 6 is 4 mm, and the total length of the jig 6 including the conical portion 7 is 80 mm. Although the material is not particularly limited, brass is used in this example.

Hereinafter, the procedure for fixing the fine tubes will be described.
First, as a first step, the jig 6 is inserted into the straightening unit 4, and the conical portion 7 of the jig 6 and the conical through-hole 2 are brought into close contact with each other. FIG. 7 shows this situation.

Next, as a second step, the fine tube 5 is inserted into the cylindrical through-hole 3 so as to be located coaxially with the jig 6.
The tip of the fine tube 5 is brought into contact with the jig 6. FIG. 8 shows this situation. The conical portion 7 at the tip of the jig 6 closes the connecting portion between the conical through-hole 2 and the cylindrical through-hole 3 so that the tip of the microtube 5 does not protrude into the conical through-hole 2 and the cylindrical through-hole 2 3, the position can be adjusted optimally.

Next, as a third step, the fine tube 5 and the cylindrical through hole 3 are bonded. As a method, heating, welding with a chemical, or the like can be considered depending on the use of an adhesive or the selection of the material of the microtube and the holding portion. In the present embodiment, a water-resistant and chemical-resistant adhesive (DP-460 manufactured by Sumitomo 3M) is injected and applied from the adhesive application side hole 8 to fill the gap between the fine tube 5 and the holding unit 1. , With the role of sealing together with fixing.

The flow cell manufactured according to this embodiment is:
The present invention can be applied to particle measurement and particle analysis in various fields including a field of sample testing such as blood analysis and urine component analysis, and an industrial field such as testing of particles such as paints, toners, and pigments.

FIG. 9 is a schematic view showing an example of a particle measuring method using the flow cell according to the present embodiment. The sheath liquid sent into the flow cell passes through the rectification unit 4 and flows into the acceleration unit (conical through-hole 2). On the other hand, the sample liquid is discharged from the jet nozzle 9 to the center of the sheath liquid. As a result, the sheath liquid and the sample liquid flow in a laminar state from the accelerating section into the orifice section (fine tube 5), and form a sheath flow. Then, the sheath liquid and the sample liquid that have passed through the orifice section are discharged from the discharge port 10.

As the light source 11, a light source such as a semiconductor laser is used.
As the light receiving unit 12, a light receiving element such as a photodiode can be used. The sample liquid flowing through the orifice section is a light source 11
The light receiving unit 12 detects optical information such as scattered light and fluorescence emitted from particles in the sample liquid. Based on the optical information, classification, counting, and the like of particles in the sample liquid are performed.

Although not shown in FIG.
Various optical devices such as a collimator, a condenser lens, and a light-shielding plate can be arranged between the light-receiving unit 12 and the light-receiving unit 12. In addition, a configuration in which a plurality of light sources and light receiving units are provided may be employed.

Hereinafter, an experiment for forming a sheath flow using the flow cell according to the present embodiment will be described. FIG. 10 schematically shows the configuration of this experiment. The laser beam emitted from the light source 11 and passing through the condenser lens 13, the micro tube 5, and the collector lens 14 is adjusted so that the image of the inner wall of the micro tube is formed on the screen 15. Then, the flow diameter of the sample liquid is measured using the fact that the boundary between the liquid and the sheath liquid forms an image on the screen as a dark line due to the difference in the refractive index. In this experiment, ethanol was used as a sample liquid, and Cellpack (II) (manufactured by Sysmex Corporation) was used as a sheath liquid.

In this experiment, in addition to the flow cell of the present invention, the same parts (holding part, microtube, adhesive) were used, but a flow cell manufactured without using the position adjusting method of the present invention was also used. The state of the image formation in was compared. Figure 1
1 and FIG. 12 show an image 16 of the inside wall of the microtube formed on the screen in this experiment, and dark lines 17 and 18 at the boundary between the sample liquid and the sheath liquid.

FIG. 11 shows an example of image formation on a screen when a flow cell manufactured without using the position adjusting method of the present invention using the same parts as the flow cell manufactured according to the present invention. Things. The dark line 17 at the boundary between the sample liquid and the sheath liquid can be confirmed inside the microtube inner hole wall image 16, and it can be said that the sheath flow is formed temporarily, but the flow is considerably disturbed and the width is widened. .

FIG. 12 shows an example of the state of image formation on a screen when the flow cell of the present invention is used. A dark line 17 at the boundary between the sample liquid and the sheath liquid is formed close to and parallel to the inside of the microtube inner hole wall image 16.
This confirms the formation of a thin and stable sheath flow.

The results of this experiment show how important and difficult it is to finely adjust the position of the microtube and the holding section.
At the same time, the experimental results show that the present invention enables accurate and easy position adjustment and fixation of the microtube and the holding portion, and that the sheath flow was formed in a favorable state in the flow cell manufactured according to the present invention. It is.

In this experiment, when the flow cell of the present invention was used, the sample liquid flow diameter of the sheath flow confirmed to be formed was 13 μm. Hereinafter, the theoretical value of the sample liquid flow diameter is obtained based on the conditions of this experiment.

First, an equation for obtaining the optimum theoretical value of the sample liquid flow diameter will be described. Assuming that the flow rate of the sheath liquid is Q _{S ,} the flow rate of _the sample liquid is Q _{C ,} the inner diameter of the orifice portion is d, the average flow velocity of the sheath liquid and the sample liquid passing through the orifice portion is v, and the sample liquid flow diameter is Dc (FIG. 13). ), From the principle of continuity,

(Equation 1) Holds.

In a laminar flow state, the velocity distribution in the pipe is parabolic, and Umax = 2v (Umax: maximum flow velocity at the center of the orifice). If Q _S ≫Q _C , the sample liquid almost flows through the center of the pipe.

(Equation 2) far. The sample liquid flow diameter D _C downstream from the above conditions is

(Equation 3) Becomes

The conditions in this experiment are as follows. d (inner diameter of orifice) = 113 [μm] (diameter of a circle corresponding to a square area of 100 μm on a side) Qc (sample liquid flow rate) = 1.4 [μL / s] Qs (sheath liquid flow rate) = 42 [μL / s ]

(Equation 4) Substituting the values of the above-mentioned various conditions into this experiment, the theoretical value of the sample liquid flow diameter in this experiment is Dc = 14.6 [μm]. Since the measured sample liquid flow diameter was 13 μm, it can be said that the results of this experiment were almost the same as the theoretical values. That is, the results of this experiment show that a sheath flow, which is indispensable for flow cytometry, was formed in a favorable state in the flow cell manufactured according to the present invention.

[0030]

According to the present invention, accurate and easy position adjustment and fixing of the conical through-hole and the fine tube can be performed, and the production of a flow cell using an inexpensive fine tube for the orifice portion can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a poor joining of a fine tube.

FIG. 2 is a view showing an example of a bonding failure of a fine tube.

FIG. 3 is a diagram showing an embodiment of a holding unit used in the present invention.

FIG. 4 is a diagram showing an example of a flow cell manufactured according to an embodiment of the present invention.

FIG. 5 is a sectional view of a fine tube used in one embodiment of the present invention.

FIG. 6 is a view showing one embodiment of a jig used in the present invention.

FIG. 7 is a view showing one embodiment of the first step of the present invention.

FIG. 8 is a view showing one embodiment of the second step of the present invention.

FIG. 9 is a diagram showing an example of a particle measuring method using a flow cell according to an embodiment of the present invention.

FIG. 10 is a diagram showing a configuration of a sheath flow forming experiment.

FIG. 11 is a diagram showing an image formed on a screen in a sheath flow forming experiment.

FIG. 12 is a diagram showing an image formed on a screen in a sheath flow forming experiment.

FIG. 13 is a view for explaining calculation for obtaining a theoretical value of a sample liquid flow diameter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Holding part 2 Conical through-hole 3 Cylindrical through-hole 4 Rectifying part 5 Fine tube 6 Jig 7 Conical part 8 Adhesive application side hole 9 Jet nozzle 10 Outlet 11 Light source 12 Light-receiving part 13 Condenser lens 14 Collector lens 15 Screen 16 Image of pore wall inside microtube 17 Dark line at boundary between sample liquid and sheath liquid 18 Dark line at boundary between sample liquid and sheath liquid

Claims (6)

[Claims] 1. A cone comprising a microtube, a holding portion having a conical through-hole connected to an end of the microtube, and a jig having a conical portion having a tapered angle in close contact with the conical through-hole. A first step of bringing the conical portion of the jig into close contact with the through hole, and disposing a microtube on the same axis of the jig from the side opposite to the jig with respect to the holding portion; A method for manufacturing a flow cell, comprising: a second step of bringing a part into contact with a conical part of a jig; and a third step of bonding a fine tube and a holding part. 2. The method for producing a flow cell according to claim 1, wherein in the cross-sectional shape of the microtube, at least one of the cross-sectional shape of the outer edge portion and the cross-sectional shape of the internal hole is a square or rectangular microtube. 3. The method for manufacturing a flow cell according to claim 1, wherein a holding portion formed by connecting a straightening portion to the conical through hole is used. 4. A cone comprising a microtube, a holding portion having a conical through-hole connected to an end of the microtube, and a jig having a conical portion having a tapered angle in close contact with the conical through-hole. A first step of bringing the conical portion of the jig into close contact with the through hole, and disposing a microtube on the same axis of the jig from the side opposite to the jig with respect to the holding portion; A flow cell manufactured by a step including a second step of bringing a part into contact with a conical part of a jig, and a third step of bonding a fine tube and a holding part. 5. The flow cell according to claim 4, wherein in the cross-sectional shape of the microtube, at least one of the cross-sectional shape of the outer edge and the cross-sectional shape of the internal hole is a square or rectangular microtube. 6. The flow cell according to claim 4, wherein a holding portion formed by connecting a straightening portion to the conical through hole is used.