chylomicrons

The chylomicrons are the largest lipoprotein particles in human plasma, and CM is the majority of dietary TG delivered from the small intestine absorption site to the systemic circulation. The CM clearing speed is fast, the half-life is 10 min, and the normal person can't detect it after 12 hours on fasting. When the lipoprotein is electrophoresed, the CM is at the origin. It should be noted that the sample should be fresh during serum lipoprotein electrophoresis and should not be stored frozen. Basic Information Specialist classification: Digestive examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Normal value: no Above normal: negative: normal. Positive: Hyperlipoproteinemia type I, hyperlipoproteinemia type V. Tips: Before the examination, the diet is light and alcohol is prohibited. Normal value negative. Clinical significance Positive hyperlipoproteinemia type I, hyperlipoproteinemia type V. Positive results may be diseases: hyperlipoproteinemia type I, hyperlipoproteinemia type V precautions 1. Immunoturbidimetric turbidity method: (1) Regarding antiserum: The turbidimetric assay has higher requirements for antiserum than other methods. The turbidimetric method is preferably a polyclonal antibody. Anti-serum must be free of anti-serum. Must pay great attention to the apoA-I extracted from human serum to achieve immunopurity, chromatographic purity and electrophoresis purity, which is not possible in the general laboratory. The antiserum titer (titer) should not be less than 16. At present, in some domestic commercial reagents, the apoA-I antiserum has a very low titer, so care must be taken when purchasing the kit. If you do not have experience in identifying antisera quality before purchase, you should ask the qualified unit to identify it. (2) The specimen in the upper method (serum) is diluted 200 times for manual operation (100 μl of sample), and if it is a precision sampler, it can be diluted 20 times (using 10 μl). In order to adapt to the conditions of different laboratories (such as different types of automated instruments), the proportion of antigen-antibody should be paid attention to when making appropriate modifications. It must be noted that there should be no antigen excess in the reaction system, and the linear upper limit should not be lower than 2.5g/L. In other words, the amount of antiserum must be sufficient, otherwise the results are low when the apoA-I is high in the specimen. At present, some domestic drug kits not only have low anti-serum titer, but the dosage of the specimens in the operation is too large (such as 3 ~ 5μl), the antibody is obviously insufficient, and the measured results are inevitably inaccurate. (3) In order to achieve accurate measurement, the calibration curve calculation results must be made in the apoA-I and B turbidimetric measurement (end point method). A certain range (low sample dosage) concentration (X) is basically linear with turbidity (Y), and linear regression calculates a certain intercept on the Y-axis (A value <0.1), so the deviation of the calculation result is calculated by single point calibration. Larger, the measured results can not accurately reflect the level of high (high low, low high). Do not neglect the accuracy of the measurement because of the simplicity of the single point method. Regardless of the type of automated instrument, you must first try the calibration curve. If the test is repeated under the conditions of the instrument and the specific conditions, the intercept of the regression line is not obvious, then the single point calibration method can be used. When the amount of the sample is 3 to 5 μl, even if the amount of antiserum is increased, the concentration and the turbidity are not linear, and can only be calculated after the curve is linearly converted. (4) The main interference factor is the turbidity of the serum itself (such as high-fat serum), and the pretreatment methods such as ultracentrifugation or lipase hydrolysis are not practical. The effect of turbidity with surfactants is also limited, so a blank tube must be made in the assay. In addition to the two-point method used in automated analysis, it is a mistake to manually use a single reagent without subtracting the specimen blank. In order to reduce the effect of matrix effects on the turbidity response, fixed-value serum must be used as a calibrator. In addition, interference such as dust particles and turbid dish scratches must be excluded. (5) Some commercial kits (including some imported products) have inaccurate calibration sera values, which are important sources of error. 2. Rocket electrophoresis: (1) The selection of the antigen dilution factor and the amount of antiserum should be clear, the slope of the calibration curve is moderate, and the alignment curve is appropriate. The method simultaneously measures apoA-I and apoB, and the amount of the two antisera should be adjusted so that the peak heights of the two are different, and the apoB peak height is not less than 1 cm. (2) Antisera from different types of sources (such as rabbits and sheep), tested at the equivalent price, the results will be different. The apoA-I assay is preferably rabbit antiserum. When the rabbit serum is used, the peak shape is sharp, and the peak produced by the sheep serum is thick, the peak tip is round and blunt, and sometimes a ghost image appears before the peak. The slope of the calibration curve for the calibration serum is also different. However, no matter what antiserum is used, the quantitative results are not much different. (3) Electrophoresis under certain conditions, the peak height of the calibration serum of different dilutions will not change significantly, and the slope of the calibration curve is basically the same. If the peak height of the specimen exceeds the calibration curve range, the specimen dilution factor should be adjusted and retested. The inter-board CV is typically less than 5%. (4) Rocket electrophoresis results can be seen by staining or direct visual observation of the rocket peak. The former uses less specimens and saves antiserum, but if the specimens and antiserum are appropriately increased, it is more convenient to not stain. The agarose used should be standard electroosmotic or hypotonic. Adding proper amount of dextran or polyethylene glycol to the gel will make the rocket peak clearer. (5) The measurement of the rocket peak can calculate the area or peak height, and the area is the peak height multiplied by the peak width (the width at the half height of the peak). The measurement accuracy is preferably up to 0.1 mm. Mechanical or electronic amplification equipment must be used. The peak height in the range of the standard curve is preferably 1 to 4 cm. (6) This Law applies to the analysis of a small number of specimens. Also suitable for apoAII, CI, CII, CIII, D, E and Lp (a) determination. Inspection process 1. Immunoturbidimetric turbidity method: (1) The specimen should be a fast-separating serum that can be separated in time. It can be stored in a refrigerator at 2 to 6 °C, measured within 1 week, and stored at -20 °C for half a year. (2) When using a fully automatic analyzer, the ratio of antigen to antibody and reaction time should be reasonably selected according to different instrument design parameters. It can also be used as a rate scatter nephelometry CM such as Beckman turbidimeter ICS or proteinarray system). (3) Instruments used in manual method: precision photometer with 340nm filter (or splitter), sample volume is preferably 0.5ml (to save antiserum), preferably with flow cup, sample dilution is best diluted Corrected sampler. (4) Specimen treatment: The serum sample and the quality control serum are diluted 1:200 with a sample diluent, that is, first diluted 1:20 (5.0 μl serum + 95 μl diluent), and then diluted 1:10 ( Excess 1:20 serum for determination of apoB). After mixing, it was allowed to stand at 25 to 37 ° C for 30 min, and was turbid at a wavelength of 340 nm. The result was read on a standard curve according to the A value of U-UB. This method has a CV of <5%. (5) Calibration curve: For each batch of manual and semi-automatic operation, a calibration curve is required, and the calibration serum can be diluted into four concentrations of 1:100, 1:200, 1:300, and 1:400, which are the same as the specimen. Operation, calculate the CM concentration of each standard tube according to the fixed value, and plot the concentration (X) with its corresponding A value (Y) (calculated by linear regression), which is basically straight, but has a certain intercept on the Y-axis. So you can't use a single point standard. When the operation is accurate, the correlation coefficient between the concentration and the A value should be above 0.985. If there are three calibration sera at high, medium and low concentrations, it can be operated in the same way as the specimen, and can be used for three-point calibration. It can also be used for five-point calibration (ie high-medium concentration serum equal mixing, medium and low Concentrations of serum were mixed in equal amounts to become the other two calibration sera). The linear range of this method: 0.4 ~ 2.5g / L. 2. Rocket electrophoresis: (1) pouring plate: 10g/L agarose 10ml per plate, melt in boiling water bath, mix well, add 50μl of CM antiserum and apoB antiserum 8μl when cold to 50~55°C (the amount depends on antiserum titer) ), quickly mix and pour on the glass plate preset on the water platform, cool and then placed at 4 ° C, after 20 min, punch holes, the hole is at the cathode end of the plate, the hole diameter is 3 mm, the hole spacing is at least 5 mm, and the hole capacity is 5 μl. Place the plate in the electrophoresis tank and bridge with filter paper. (2) Dilution of antigen: The calibration serum was diluted to 1:100, 1:150, 1:200, 1:300, and 1:400 (for calibration curve) with 0.15 mol/L NaCl solution, and the serum sample was 1: Diluted in 200, put the refrigerator at 4 °C for no more than 3 days. (3) Loading: 5 μl (accurate) of the diluted serum and specimens were taken in a low current state (10 mA/plate) and added to the agarose gel sample well. Each board has to do a series of standards. (4) Power-on: steady flow 24 mA / plate, terminal voltage 6 ~ 8V / cm, cooling with running water to maintain agarose 15 ° C, electrophoresis 3 ~ 4h. (5) Deproteinization and dry film: The agarose plate after electrophoresis was immersed in 0.15mol/L NaCl for 30min, and the film was placed on the polyester film, and dried by light pressure under a multi-layer filter paper. The moisture in the glue is then dried naturally with the filter paper, the film and the polyester film, or dried by a hot air blower. After drying, the film is naturally separated from the filter paper and the polyester film. (6) Dyeing: The agarose film was immersed in the staining solution for 20 to 30 minutes. (7) Decolorization: Soak the dyed film with a decolorizing solution until the rocket peak is clear, and the background is basically colorless. It can be clamped in two pieces of cellophane in water and can be stored for a long time after drying. It can also be soaked in running water to remove the background. Note: 1 The dilution ratio of the antigen and the amount of antiserum should be selected so that the rocket peak is clear, the slope of the calibration curve is moderate, and the line is suitable. The method simultaneously measures apoA-I and apoB, and the amount of the two antisera should be adjusted so that the peak heights of the two are different, and the apoB peak height is not less than 1 cm. 2 Different kinds of antiserums (such as rabbits and sheep) are tested at the equivalent price, and the results will be different. The apoA-I assay is preferably rabbit antiserum. When the rabbit serum is used, the peak shape is sharp, and the peak produced by the sheep serum is thick, the peak tip is round and blunt, and sometimes a ghost image appears before the peak. The slope of the calibration curve for the calibration serum is also different. However, no matter what antiserum is used, the quantitative results are not much different. 3 Electrophoresis under certain conditions, the peak height of the calibration serum of different dilutions will not change significantly, and the slope of the calibration curve is basically the same. If the peak height of the specimen exceeds the calibration curve range, the specimen dilution factor should be adjusted and retested. The inter-board CV is typically less than 5%. 4 Rocket electrophoresis results can be observed by staining or direct visual observation of the rocket peak. The former uses less specimens and saves antiserum, but if the specimens and antiserum are appropriately increased, it is more convenient to not stain. The agarose used should be standard electroosmotic or hypotonic. Adding proper amount of dextran or polyethylene glycol to the gel will make the rocket peak clearer. 5 The measurement of the rocket peak can calculate the area or peak height, and the area is the peak height multiplied by the peak width (the width at the half height of the peak). The measurement accuracy is preferably up to 0.1 mm. Mechanical or electronic amplification equipment must be used. The peak height in the range of the standard curve is preferably 1 to 4 cm. 6 This method is applicable to the analysis of a small amount of specimens. Also suitable for apoAII, CI, CII, CIII, D, E and Lp (a) determination. Not suitable for the crowd no. Adverse reactions and risks no.