JPS6236531B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for automatically detecting the measurement length of a sample in a densitometer. Concerning a method for automatically detecting a measurement length that is always valid for that measurement regardless.

A densitometer is a device that automatically measures and records the concentration of each component such as serum protein from a specimen sample (electrophoresis pattern) fractionated on a specimen support by electrophoresis. In recent years, with the remarkable increase in the number of specimens per day, facilities that require processing of a large number of specimens, such as hospitals, medical facilities, or testing centers, have exclusively used so-called densitometers for large-volume specimens.

In most of the above-mentioned densitometers for large amounts of samples, multiple samples (usually 10 to 20 samples) are arranged at regular intervals in the lateral direction (so-called X-axis direction) on the same flat support, as shown in Figure 1. Then, an electrophoresis support on which a plurality of components of each sample are migrated on a straight line in the vertical direction (so-called Y-axis direction) is held in a frame such as a cassette, and the frame is attached to an optical system detection section. On the other hand, the fractional concentrations of multiple samples can be automatically measured by moving the electrophoresis support in the vertical and horizontal directions, or by moving the optical system detection section in the vertical and horizontal directions with respect to the electrophoresis support. It is known that the densitometer for large quantities of samples records continuous data together with a fractional densitometric diagram, and by setting a plurality of the above-mentioned electrophoresis supports (usually 5 to 10) in the densitometer for a large amount of sample, it is possible to record, for example, several dozen or more electrophoresis supports. Many of them are configured to sequentially and continuously measure multiple samples.

When such a densitometer is used to continuously process a large number of samples, various problems mainly related to the sample support and electrophoresis itself arise, as described below.

(a) For example, applying a sample to a support such as a commercially available separat membrane is almost done manually, and although it may seem simple and easy at first glance, in reality it requires considerable skill to prevent coating errors that can cause various migration shifts. degree is required. Furthermore, in addition to requiring a lot of effort and time, there are significant individual differences.

(b) Applicators (specimen applicators) are also commercially available, but they are insufficient in performance and ease of use, and are still far from becoming widespread.

(c) The total length (vertical direction) of the electrophoresis pattern of each sample depends on electrophoresis conditions such as the type of support, the PH degree of the buffer solution, the temperature, the extent to which the buffer solution is new or old, the magnitude of current and voltage, or the electrophoresis time. It is not constant and typically varies significantly from one electrophoretic support to another.

Next, the following are practical problems that arise when the electrophoretic pattern is moved vertically and horizontally relative to the optical detection section to measure its concentration.

(a) If the vertical movement distance of the analyte sample (transport table) of the densitometer is set to a constant value, if the total length of the electrophoresis pattern is short, it will be possible to detect parts of the analyte sample that do not need to be measured, and it will take a considerable amount of time. On the other hand, if the total length of the electrophoresis pattern is long, the portions of the sample that need to be measured may not be detected, which is a problem.

(b) Therefore, the length of the sample to be measured must be measured each time by the operator using a scale, or the length must be determined and set by performing trial measurements several times with the device, which is cumbersome. This not only takes time and effort, but also causes measurement errors due to differences between samples.

(c) The above operation must be performed for each cassette.
Not only does this add up to the same amount of effort and time as in item (b) above, but it also poses a major hindrance to the automation of the densitometer itself.

(d) Base (first
The concentration of the outer part of γ-globulin 2, which is located directly opposite to albumin (marked by reference numeral 1 in the figure) and is the thinnest and almost transparent part with an unclear border with γ-globulin 2, is determined by the specimen sample. Moreover, it is almost impossible for an operator to judge the sample measurement length only by changing the voltage level by the optical sensor of the densitometer or by visual judgment.

The present invention solves the unavoidable drawbacks of the conventional large-volume sample concentration meter described above, eliminates the trouble of measuring the length or trial measurement each time for a sample electrophoresed under any conditions, and saves time and effort. The purpose of this invention is to provide a method for automatically detecting the effective sample measurement length and achieving true full automation of the densitometer. explain.

(a) First, the movement mechanism of the densitometer moves the first electrophoretic pattern in the vertical direction from the starting point O to the ending point P (as shown in Figure 5) of its movement path, and its concentration is detected at regular intervals by an optical sensor. All of the above data converted into digital quantities is stored in a microcomputer.

(b) Next, in order to eliminate the influence of the shading of the base of the electrophoresis pattern that makes it impossible to detect the sample measurement length, zero base correction is performed on all the data stored in the memory in the above section (a). This means that the fractional diagram of the electrophoresis pattern obtained by the densitometer is, for example, the second
If it is as shown in Figures A and B,
The base of A is L, and the base of B is l, creating a base difference L-l between the two. This base difference is
This is a natural result because both migration patterns are different.

Now, erase both bases L and l above,
As shown in diagrams A and B of FIG. 3, zero-based correction processing is performed. Through this correction process, the sample measurement length can be detected under the same conditions even for specimens having different base concentrations, as will be described later. The above correction process can be easily performed by subtracting the base value of each sample from the data stored in the memory of the microcomputer.

(c) Next, since the electrophoresis pattern of each sample usually causes a difference in overall concentration depending on its electrophoresis conditions, in order to make these conditions the same, the maximum value of each data is set to 2O.D. (optical density). That is, the fourth
The image shown in A of the figure is amplified to that shown in B of FIG. 4. The data processing in this case will also be performed by a microcomputer.

(d) Next, after completing the first detection in section (a) above, the migration pattern was returned to the starting point O in the vertical direction from the stopped position, and during this time, the processes in sections (b) and (c) above were performed. The amount of change from the zero base is calculated for the data.

Now, if the base point where the amount of change becomes continuously larger than a predetermined reference value is Q point, this Q point is, for example, a position corresponding to the fractionation point of γ-globulin in the case of a protein migration pattern. , becomes the final point of the desired measurement length of the specimen sample. In addition, when detecting the above Q point, in order to prevent false detection due to dirt or dust on the pattern, the above reference value should be slightly larger than the density (OD) that increases due to dirt or dust. Setting the value.

The position of Q point is determined by a microcomputer.
It is immediately calculated by the following method. That is, if the total number of samplings from the first detection start position O to the detection end position P is N, and the number of samples from the detection end position P to the first change point Q is n, then the sample measurement length S is the number of samplings mentioned above. N and n
It is determined by the formula below.

S=N-n/NxS' Here, S' is the length of the vertical travel stroke determined by the densitometer and is a constant.

By the method described above, once the measurement length of the first sample is detected, the above measurement length can be applied to the next electrophoresis pattern (patterns on the same electrophoresis membrane have almost the same length). In the case of other electrophoresis patterns using different cassettes, it is sufficient to detect the measurement length once using the method of the present invention for the first sample in the cassette.

Next, FIG. 6 is an explanatory diagram showing only relevant parts of a block diagram for carrying out the present invention, in which 10 is an optical system, 11 is an electrophoretic pattern, and 1 is an explanatory diagram showing only relevant parts.
2 is a detector, 13 is an A/D converter, 14 is a memory device, 15 is a fraction determination circuit, 16 is a recording device, and 17 is a sample measurement length determination mechanism, which is a feature of the present invention.

When measuring the fractional concentration of the migration pattern of a large amount of sample using the method of the present invention described above,
As in the conventional method, the electrophoresis pattern is simply set at a predetermined position on the densitometer and moved in the vertical and horizontal directions, thereby automatically detecting the effective measurement length of the first sample. This can be applied to other electrophoresis patterns, and when using different cassettes, the measurement length can be measured for the first sample as described above.

Above, in the method of the present invention, the case where the densitometer is of a type in which the electrophoretic pattern of the sample is moved vertically and horizontally with respect to a fixed optical system detection part has been explained. The same applies to the case where a fixed electrophoresis pattern is moved in the vertical and horizontal directions.

The main effects of the present invention are listed below, and it plays an extremely important role not only in general measurement but also in medicine.

(a) There is no need to modify or add to the sample or optical system detection unit moving mechanism of the conventional model.

(b) There is no need to measure the sample measurement length each time the concentration is measured, which simplifies the operation.

(c) Eliminate measurement errors and improve data reliability.

(d) Even when the migration length of the sample pattern is not constant, the measurement length of the sample can be automatically detected, eliminating the need for the densitometer operator to constantly monitor the machine and allowing for continuous measurement, i.e. a complete form of automation. It becomes possible.

(e) In particular, it is possible to automatically measure a large amount of samples (for example, 200 or more samples) by using multiple cassettes.

(f) It can be used for any sample electrophoresed under a variety of different conditions.

[Brief explanation of the drawing]

Figure 1 shows a normal electrophoresis pattern for multiple samples, Figures A and B in Figure 2 show two types of fractionation diagrams, and Figure 3 shows A.
Figures 1 and 2B show fractional diagrams obtained by applying zero-base correction to those in Figures A and B of Figure 2, respectively. A in Figure 4
The figure shows the fractionation diagram before OD amplification correction, and the B diagram in Fig. 4 shows the fractionation diagram after the same correction. FIG. 5 is a one-section diagram for explaining the method of detecting the measurement length of a sample. 6th
The figure is an explanatory diagram showing only relevant parts of a block diagram for implementing the present invention. 10...Optical system, 11...Migration pattern, 12
...detector, 13...A/D converter, 14...memory device, 15...fraction determination circuit, 16...recording device, 17...sample measurement length discrimination mechanism.

Claims (1)

[Scope of Claims] 1. A sample in which a plurality of specimens are arranged at regular intervals in the horizontal direction on the same planar support and a plurality of components of each specimen are migrated on a straight line in the vertical direction is optically analyzed. In a densitometer that measures the fractional concentration of the analyte by moving the optical system detection unit in the longitudinal and lateral directions relative to the electrophoresis support, or by moving the optical system detection unit in the longitudinal and lateral directions relative to the electrophoresis support, the first electrophoresis pattern Alternatively, the optical system detecting section is moved vertically from the starting point O to the ending point P of the movement process to detect and store the density data, and then after performing zero base correction and optical density amplification on the above data, from the point P. Return the point between points O, and during that time sequentially detect and compare the amount of change from the zero base, find the base point Q when this value becomes continuously larger than a predetermined reference value, and set the point O,
If the distance between points P and the total number of samples are S' and N, respectively, and the number of samples between points P and Q is n, then the sample measurement length S can be found from the formula S=N-n/N×S' A method for automatically detecting a sample measurement length in a densitometer, characterized in that the method is configured as follows.