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POCT concept, basic principle and main technique

Dec 23, 2017

POCT refers to the analysis of a patient's specimen next to the patient, or POCT as long as the test is not performed in the main lab and it is a mobile system. The POCT consists of: Location, Time, Care, Care, Testing, Testing, point-of-care testing Literally literally means health examinations at the site of a subject.

The basic principle of POCT is that the relevant liquid reagent in the traditional method is infiltrated into the water-absorbing material of the filter paper and various microporous membranes to become an integrated dry reagent block, and then fixed on a rigid substrate to be in various forms Of the diagnostic reagent strip; or the miniaturization of conventional analytical instruments, methods of operation is simplified, making it a portable and palm-type devices; or both of them into a unified system.

 POCT's main technologies include:

(1) Simple color development (dry chemical method) The technique dries and fixes a plurality of reaction reagents on a piece of paper, and adds a color reaction after the test specimen (whole blood, serum, plasma, urine, etc.) Or instrument detection (semi-quantitative).

(2) Multi-layer coating (dry chemical method) technology Multi-layer coating technology is transferred from the production of photosensitive film technology. Will be a variety of reagents in turn coated on the base, made of dry film, with the instrument test, you can accurately quantify.

(3) Immunogold labeling technology Colloidal gold particles have the characteristics of high electron density, gold standard protein binding, dark brown particles can be seen under a microscope, when these markers in the corresponding mark a large number of accumulation, the naked eye can see red or pink Spots, this reaction can be amplified by the deposition of silver particles. Such techniques are mainly dot immunofiltration (DIGFA) and immunochromatography (ICA).

(4) Immunofluorescence Quantification of single or multiple markers on the test strip in pg / ml by quantitatively detecting laser-induced fluorescence on the strip. The detection system usually consists of a fluorescence reader and a detection plate. Multi-chromatography detection board, the analyte in the process of moving the formation of immune complexes, through the detection region, the quality of the control region of the fluorescence signal value of the different concentrations of analyte into a certain ratio, calibration curve can be detected Unknown sample analyte concentration.

(5) Biosensor technology The use of ion-selective electrode, substrate-specific electrodes, conductivity sensors and other specific biological detectors for analysis and testing. Such technology is the product of enzyme chemistry, immunochemistry, electrochemistry and computer technology.

(6) Biochip technology Biochip is the latest development of new technologies. It is characterized by simultaneous measurement of multiple items on a small area of the chip. Biochips can be divided into gene chips, protein chips and cell chips. They have the characteristics of high sensitivity, short analysis time, multiple items that can be detected at the same time.

(7) Infrared and Far-infrared Spectrophotometry These techniques are commonly used in transdermal instrumentation to detect hemoglobin, bilirubin, and glucose in the blood. This bedside testing device continuously monitors the blood components of the patient without the need for blood to avoid possible cross-contamination of blood samples and contamination of blood samples, reducing the cost per test and shortening the reporting period.