Automatic biochemical analyzers have a variety of classification methods, the most commonly used is the structure of the reaction device according to its classification. According to this method can be divided into two categories of automatic biochemical analyzers mobile and discrete.
Flow-type automatic biochemical analyzer is the determination of the same items to be tested samples and reagents mixed with the chemical reaction in the same pipeline flow process is completed. This is the first generation of automatic biochemical analyzers. In the past, how many channels of biochemical analyzer refers to this category. There is a more serious cross-contamination, the results are less accurate, has been eliminated.
Separate automatic biochemical analyzer and the main difference between the flow type is that each sample to be tested and reagent mixing between the chemical reaction is completed in their respective reaction dish, not easy to cross-contamination, reliable results. Air Segmentation System
This analyzer is characterized by a proportional quantitative pump squeeze elastic sample tube, air tube and reagent tube (commonly known as the "pump tube"), the sample will be continuously inhaled in turn and transported along the sample tube, on the other hand, the air bubbles from the air tube will be inhaled by the same principle and continuous flow of reagents in the reagent pipeline. On the other hand, the air bubbles drawn in by the air tube divide the reagent, which is drawn in by the same principle and flows continuously in the reagent pipe, into homogeneous sections, and the sample and reagent streams meet, mix, permeate (if necessary), hold, react, and are measured in the continuous forward flow. The entire analytical process is accomplished as the liquid stream flows continuously through the pipeline.
Non-segmented systems
Non-segmented systems rely on reagent blanks or buffers to space the reaction solution for each sample so that the continuous flow of liquid in the pipeline is not segmented. Non-segmented systems can be subdivided into flow injection systems and gap systems.
1, flow injection system: the composition of the system is similar to the air segmentation system, but some of the structure and working principle is different, the air segmentation system is the use of air bubbles segmentation to prevent the pipeline in the flow of each reaction liquid in the flow of cross-contamination, while the flow injection system is through the sample is injected into the reagent flow pipeline of the continuous flow of the sample in turn to achieve the purpose of preventing cross-contamination.
2, gap system: the structure, composition and working principle of the system is similar to the flow injection system, but it is characterized by each injection must be in the previous sample after the end of the analytical process (including pipeline cleaning) to start, and can not be continuous sequential injection of samples, each time between the injection of samples there is a time lag, so it is referred to as discontinuous flow analyzers. Discrete for the second generation of automatic biochemical analyzers, it is the main difference with the flow type is that each sample to be tested and reagents mixed between the chemical reaction is completed in their respective reaction dish.
The centrifugal automated biochemistry analyzer, known as the third generation of automated biochemistry analyzers, should also belong to the discrete type. Because in the centrifugal analyzer, each sample to be measured in the centrifugal force, in the respective reaction tank and reagent mixing, and complete the chemical reaction, and then be measured. Centrifugal analyzer belongs to the "synchronous analysis", under the action of centrifugal force, the sample to be measured almost simultaneously with the reagents mixed, reacted and measured and typed out the report; while other analyzers are "sequential analysis", that is, the samples to be measured in turn with the reagents mixed, reacted and measured. The other analyzers are "sequential" in that each sample is mixed with the reagent, reacted with the reagent, and measured in turn.
Bag type automatic biochemical analyzer should also belong to the discrete, it is a reagent bag instead of the reaction tube and cuvette, the determination of each sample to be tested in their own reagent bag for reaction and detection. There is also a kind of analyzer called "dry automatic biochemical analyzer" also belongs to the discrete type. Its main feature is the use of solid-phase chemical technology, that is, the reagents are solid-phase on film or filter paper and other carriers. Measurement of a certain amount of the sample to be measured distributed on a piece of test paper, after a certain period of time with a reflectance photometer.
Split-type automatic biochemical analyzer, is the current laboratory commonly used automatic biochemical analyzer, generally can be arbitrarily selected for the determination of the project, so it is called optional automatic biochemical analyzer. The following will focus on optional automatic biochemical analyzer. Sampling system
1, the sample carousel: can be placed in small sample cups dozens. Some analyzers can be used directly with a sample of the test tube, some also has a bar code reading device that can identify the sample tube on the bar code information, do not need to give the sample number, but also do not have to enter the patient's information can be printed out the patient's laboratory report.
2, reagent room (warehouse): different analyzers reagent room can accommodate a different number of reagent kits, generally can accommodate more than 20 kinds of reagents. Some reagent rooms with refrigeration devices, reagent rooms with bar code identification device reagents can be placed in any reagent box location.
3, sampling device: some analyzers to take samples and reagents to take the same sampling needle, by the internal shunt valve control to take samples and reagents; some instruments have two sets of sampling devices, respectively, to take samples and reagents. The front end of the sampling needle has a liquid level sensor to prevent empty suction or liquid hanging shower on the outer wall of the sampling needle, and there is a preheating device in the sampling arm. If the multi-reagent analysis method is used, it will occupy the position of the reagent box in the reagent chamber, which will reduce the number of measurement items.
Sample system
1, sample library: 65 sample spaces, can be placed in a variety of original blood collection tubes, test tubes and micro sample cups. And there are two sample trays, which can be exchanged for any use.
2, sample volume: 2.5ul ~ 40ul, determined at the time of project preparation, the instrument automatically sampling, 0.05ul increment.
3, sample needle: with liquid level automatic detection and anti-collision safety protection.
4, sample needle cleaning: in addition to the special cleaning solution for the internal and external surfaces of the sample needle rinse, but also with warm distilled water rinse the outer surface of the sample needle, hot air blow dry.
Operating system
1, software operating system: Windows XP
2, data processing: storage, output a variety of test data and charts (including the project's calculation results) without time and storage capacity limitations.
Colorimetric system
1, light source: most analyzers use halogen tungsten lamps, working wavelength of 325 ~ 800nm. some analyzers use xenon lamps, working wavelength of 285 ~ 750nm.
2, colorimetric cups: there are discrete cuvette cups, discrete carousel cuvette, centrifugal cuvettes, flow cell. Dry biochemistry does not need a colorimetric cup, bag biochemistry by the reagent bag by extrusion automatically form a colorimetric cup. The optical diameter of the colorimetric cup is 6-7mm, and a few of them are 10mm.
The reaction solution in the colorimetric cup needs to be kept at a constant temperature, and there are three grades to choose from: 37℃, 30℃, and 25℃, and some of them are fixed at 37℃. Most use blowing into the thermostatic air, but also use a thermostatic water bath or semiconductor temperature control device.
In order to ensure that the reaction solution in the colorimetric cup has an accuracy of ± 0.1 ℃, the analyzer's ambient temperature must be maintained at 18 ~ 30 ℃, room temperature fluctuations should not exceed 2 ℃.
3, monochromator: (1) interference filter (2) grating
4, detector: (1) photomultiplier tube, has been rarely used. (2) array solid-state photodiodes.
Water supply and drainage system
Automated biochemical analyzers have a lot of water supply pipes and solenoid valves. Read-only memory in the software parameters control solenoid valves and infusion pumps to supply the various components of the rinse and suction, and finally discharged out of the machine. Random memory analysis parameters control solenoid valves and syringe stepper motor, supply samples, reagents and dilution of water. Some biochemistry instruments also automatically rinse the colorimetric cup for repeated use.
Data processing system
The test results of each item are temporarily stored in the random memory, and when all the items required for a particular sample have been tested, the microcomputer summarizes and prints out a comprehensive report card. The memory of the microcomputer can store a considerable amount of patient data and day-by-day indoor quality control data, which can be called up at any time according to the instructions, displayed on the fluorescent screen or printed, and can also be stored on a floppy disk for long-term preservation and access at any time.
Analysis sequence
Each sample can be tested for one or all of the items in the preset kits in the reagent chamber. The microcomputer arranges the order of project testing according to the inputted instructions, generally doing the endpoint method with long incubation time first, followed by the rate method with short monitoring time, in order to print the comprehensive report form at a constant speed. When the specified sample into the position to be tested, the microcomputer command reagent box into the reagent sampling position, according to the parameters of the project measured by the sampling system quantitative sampling, while the colorimetric cup according to the instructions of the microcomputer to reach the designated position to add samples. The analysis speed of biochemistry instrument and instrument sampling cycle time is related. The shorter the sampling cycle time, the faster the analyzer speed. The double reagent method occupies two dosing cycles and halves the analyzing speed.
Analysis parameters
1, test code 14, continuous monitoring time
2, test name 15, the number of standard liquid
3, test method 16, the concentration of the standard liquid
4, the type of test 17, the number of times of repetition of the calibration
5, temperature 18, the calculation of the factor (F-value)
6, wavelength Wavelength：Primary wavelength and secondary wavelength can be selected. 19、Units of Measurement
7、Reaction Type 20、Decimal Point Digits
8、Zero Reading of Endpoint Method 21、Substrate Depletion
9、Sample Volume and Dilution Volume 22、Linearity
10、Reagent Volume and Dilution Volume 23、Reagent Absorbance Upper and Lower Limits
11、Sample Blank 24、Linear Range
12, incubation time 25, reference range
13, delay time
The use of analytical parameters
(a) Instrument manufacturers to provide the determination of the project
1, the famous instrument company produces its own common items reagent kits, calibration solution (fixed-value serum-type standard solution) and fixed-value quality control serum to provide about 30 kinds of commonly used analytical parameters of the project for users to use directly. The analytical parameters of about 30 common items are provided for direct use by users. In addition, there are dozens of blank item parameter lists for users to develop new items by themselves.
2, some famous instrument companies do not provide their own reagent kits, but there is a cooperative reagent company, the cooperative reagent company to provide analytical parameters. Therefore, when you buy the instrument, you must buy a certain number of reagent kits from the specified reagent companies (including calibration solution and quality control serum).
3, small instrument companies neither produce reagent kits nor cooperative reagent companies, the analytical parameter table is empty, users need to design their own analytical parameters, so it is very difficult. However, domestic agents generally provide their design parameters, often individual parameters are not appropriate, the user should verify their own article by article.
(ii) the best use of the manufacturer's original parameters
1, the original analytical parameters should not be modified, only the unit of measurement should be selected from our legal units. With the original company's designated reagent kits, calibration solution and the fixed value of quality control serum for indoor quality control, unless the analyzer is not debugged or faulty, generally can be passed at once.
2, different companies of the calibration solution used in the calibration of the original standard of different sources, the value can be slightly different. Methodology of the same reagent kit formulations also have differences, so other companies calibration solution or aqueous standard solution for instrument calibration, the use of non-specified reagent kit for quality control, the measured value of the serum with the quality control of the expected value of the difference, this situation does not mean that the original analytical parameters are not appropriate.
3, the quality of domestic kits has been greatly improved, you can choose the same methodology of high-quality domestic kits and the original company designated kits for parallel testing, the experimental samples should include low and high values, the results of the correlation analysis. Those that meet the requirements can be used. The methodology of a few projects does not meet the requirements of domestic reagent kits, only a separate arrangement for the project's domestic reagent analysis parameters. But the original parameters to be retained or backup, waiting for qualified domestic reagent kits to appear.
4, regardless of the original company or domestic reagent kits, the original analytical parameters should not be arbitrarily modified, especially the main parameters; such as serum reagent ratios (including the amount of diluted water), incubation time, delay time, detection time, because once these parameters are changed, the linear range and a variety of limit parameters will be changed, which will seriously affect the accuracy of the results.
5, dual-reagent two-step methodology has many advantages, if the analyzer for the dual-reagent type, it is best to use dual-reagent two-step method.
6, substrate depletion parameters can not be deleted, otherwise the results of the high concentration of low values; linear range if deleted, the results of the high concentration will also be low; reagent absorbance upper and lower limits such as the deletion of the analyzer will accept the deterioration of the reagent.
(C) the principle of their own design of analytical parameters
If the instrument company does not provide analytical parameters or determination of the project's methodology is different, you can set up their own analytical parameters. The main design of the following parameters.
1, sample reagent ratio. 6, calculation factor.
2, Incubation time. 7, substrate depletion limit.
3, Delay time. 8, Linearity.
4, Monitoring time. 9, Linearity range.
5, Reagent absorbance upper and lower limits.
These parameters are generally provided in the kit manual, can be filled in according to the analytical parameters table, calibration can be carried out after the daily work, some parameters in the future work of the gradual correction.