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< "color: > (70,135,221); ">"
1. Master the principles and methods of determining total cholesterol by high-speed rail-sulfuric acid color-showing< "> serum total cholesterol.
2. Understanding the normal value and clinical significance of serum cholesterol.
cholesterol is a derivative of cycloprene polyhydrophytes, which not only participates in the composition of plasma proteins, but is also a necessary structural component of cells, especially abundant in nerve tissue and adrenal glands, and also contains a lot of tissue in the liver, kidneys and epithets. Cholesterol is an important part of biofilm and neuromedical myelin, and it is indispensable to maintain the normal flow of biofilm.
cholesterol can also be converted into bile acid, steroidshormonesvitamin D3 and so on. Cholesterol is mainly excreted from the body with bile. Less than 20% of cholesterol in the blood is ingested from food, and the rest is synthesized by the body itself, with the liver, intestines, kidneys, bone marrow and endocrine glands all being synthesized.
because blood and tissue cholesterol are constantly exchanged, serum cholesterol levels are essentially a response to cholesterol intake, synthesis, and transfer. Cholesterol and atherosclerosis and so on have a certain link, according to foreign reports of long-term low cholesterol in the body, is one of the factors that induce cancer.
, cholesterol determination is one of the most common clinical tests. Cholesterol is present in the body in the form of free cholesterol (freecholesterol, FC) and cholesterol esters (CE), collectively known as total cholesterol.
total cholesterol determination methods are now more than 200 kinds, can be divided into chemical reagent color, enzyme analysis, fluorescence, gas phase and high-efficiency liquid phasechromatography method and other five categories. Due to the high gas phase and high-efficiency liquid chromatography conditions, the most commonly used chemical reagents and enzyme methods in clinical laboratories.
< a href> "chemical reagent method generally includes four stages: withdrawal, saponification, purification, color color ratio.
the chemical method to determine the color of total cholesterol is divided into three main categories:
(1) and acetic anhydride-sulfuric acid reagents to produce blue-green. Cholesterol esters and cholesterol are colored differently in response to acetic anhydride-sulfuric acid, so the results are high in this way.
(2) produce fuchsia with high-speed rail-sulfuric acid reagents. High-speed rail-sulfuric acid is more sensitive than color method, color stability, good precision determination, is the recommended method for clinical testing of cholesterol. But there are many distractions.
(3) cholesterol and phthalates formaldehyde-sulfuric acid reagents produce stable fuchsia. Phthalates-sulfuric acid coloring does not require the withdrawal of cholesterol and is measured directly.
ase method is the current conventional application method, its advantages are fast and accurate, single-use, sample dosing is small, no need to draw, easy to automate analysis and batch determination, is the Chinese Medical Association testing society recommended the conventional method of cholesterol determination.
high-speed rail-sulfuric acid coloration method to determine the total serum cholesterol is the use of isopropyl alcohol for solvents to extract serum cholesterol, isopropanol cholesterol withdrawal to add high-speed rail-sulfuric acid color agent, cholesterol and color agent reaction to produce a stable fuchsia compound, color depth and cholesterol concentration in direct ratio, can be compared to color determination.
equipment and reagents"
1. equipment with plug test tubes, micro-pipers, 721 terracometers, quick mixers, centrifuges,thermostats water tank.
2. Reagent
(1) isopropyl alcohol (AR)
(2) iron triclosan storage fluid: 0.1g/gt;, called FeCl3.6H2O AR, dissolved in 100 ml of ice acetic acid.
(3) color agent: iron tachloride storage liquid and thick sulfuric acid (AR) are mixed at a volume of 1:1.
(4) 5.17mmol/L Cholesterol Standard Storage: Precise weighing of recrystrogenic cholesterol (MW 386.66) 200mg, dissolved with isopropyl alcohol and diluted to 100ml, stored in the refrigerator.
(5) Cholesterol Standard Solution: 5.17mmol/L Cholesterol Standard Storage 4 ml, moved into a 100 ml capacity bottle, plus isopropyl alcohol to the tick line.
operating procedure
1. Take serum 0.1 ml, place in a plug test tube, blow to the bottom of the tube Into isopropyl alcohol 2.4 ml, the serum is washed away, so thatprotein precipitation, mixed with congestion and placed in a 60 degrees C / gt; water bath 1 to 2min. Then, mix 15s on the quick mixer. Centrifugation (3000r/min) 5min, take the extract for use.
2. Take < a href" > three test tubes, marking blank tubes, standard tubes and test tubes respectively, and adding reagents to the table below.
test tube number | blank tube | < td valign="top" width="142" >
test tube
Cholesterol Standard Liquid (ml)
-
1
->
-
withdrawal (ml)
-
-
1
isopropanol (ml)
1
-
-
60 degrees C / 1min
color solution (ml)
3
3
3
60 degrees C / sgt; water bath insulation 15min
, the wavelength of 540nm is selected to color with blank tube zero. Read and note the absorbent.
//gt;
/?gt;/gt;gt; /gt; |
normal value: 3.10 to 5.70mmol/L
note"
the withdrawal liquid and color agent mixed to generate heat, the degree of heat and color depth is related, so the operation should be noted:
1. the same batch of specimens when the test tube of the same calibre and thickness is required. In order to facilitate rapid mixing, the test tube caliber is preferably larger.
2. Add a color agent along the pipe wall, divide the isopropyl alcohol withdrawal into two layers, and then mix quickly. Do not shake side by side, otherwise the color display is not complete.
3. The color agent must be mixed with one tube, not added together, and the mixing method must be consistent.
clinically significant
the normal value of adult cholesterol is: 1100 to 2300mg/L (2.82 to 5.95mmol/L) total cholesterol increased, commonly found in the following diseases:
1. hypothyroidism, atherosclerosis, coronary atherosclerosis heart disease and hyperlipidemia.
diabetes: Especially when you're in a coma with diabetes, there's almost always an increase in total cholesterol.
3. Chronic nephritis nephropathy, nephropathy syndrome, lipid-like nephropathy, etc.
. When the bile duct is blocked, total cholesterol increases and is accompanied by jaundice, but the ratio of cholesterol to total cholesterol is still normal.
cholesterol can also be elevated during long-term high-fat diets, stress or pregnancy.
6. familial hyperglobulinemia (LDL-containing) and familial lipoprotein deficiency β and mixed hyperlipidemia.
of total cholesterol is found in the following
: hyperthyroidism, malnutrition, chronic expendable diseases.
2. Familial β or β lipoproteinemia.
points out the most commonly used methods of serum cholesterol determination in clinical practice, and compared with this experimental method, points out their advantages and disadvantages.
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