In recent years, the proportion of clinical Gram-negative bacteria (G-bacteria) infection has been increasing, and the resulting sepsis and endotoxemia are one of the common causes of death in patients. Endotoxin (ET) testing in humoral fluid can make early diagnosis of G-bacteria sepsis and endotoxemia, which has important clinical significance.
In 1923, Seibert proposed the rabbit pyrogen test (RT) for the testing of endotoxins. Existing humoral endotoxin testing methods are mostly based on the principle of LAL test. In recent years, immunological methods, biological methods, and thin-layer chromatography have also been applied to the testing of endotoxins in body fluids.
The rabbit pyrogen test is based on the biological characteristics of endotoxin pyrogenicity. The body temperature of rabbits injected with the side sample was observed to determine the endotoxin in the prescribed time. The rabbit pyrogen test method has been mainly used for drug endotoxin testing. The force method has low sensitivity and has been used less frequently.
LAL test is a kind of arthropod. Amebocytes in the blood contain factor C, factor B and proclottin-gEnzyme, which can be activated by endotoxin. The activated coagulase can make the coagulation in the deformed cells coagulagen is coagulated to form coagulated proteins, which can be used for qualitative, semi-quantitative and quantitative determination of endotoxin. The reaction has high sensitivity (pg/ml) and specificity. It can be divided into gel method, turbidity method and color matrix method.
In order to eliminate the pollution of exogenous endotoxin, the vessels and samples used for the testing of endotoxin in body fluids require pretreatment. The utensils used should be roasted at 250℃ for at least 2 hours to inactivate exogenous endotoxin. Body fluid samples are mainly blood, urine, and cerebrospinal fluid. When the limulus test is used to detect bacterial endotoxin, there is no interference in urine and cerebrospinal fluid, and no special treatment is required. Samples are usually collected by sterile and pyrogen-free methods, and placed in sterile and pyrogen-free test tubes. If the sample is turbid, centrifuge the supernatant. Blood samples contain disturbing substances and the pretreatment is more complicated. Diluted heating method, chloroform extraction method, ether treatment method, perchloric acid method, and modified perchloric acid dip and compound method are usually used.
Many clinical laboratories have developed body fluids endotoxin testing, which are mainly used for the diagnosis of the following diseases:
The routine diagnosis of sepsis is the blood culture method, which takes time (at least 24-48 hours). The determination of blood endotoxin content is of great significance for the early diagnosis of G-bacterial sepsis. Determination of endotoxin content on the surface of monocytes in peripheral blood has diagnostic significance for G-bacteria sepsis. Under the premise of improving the method to improve the sensitivity of detecting endotoxin in body fluids, directly measuring the content of endotoxin in the blood has certain advantages for the diagnosis of G-bacterial sepsis. But at the same time, we should consider the interference of bacterial species, endotoxin release and fungal infection.
The endotoxin test sample for patients with pulmonary infection can be extra-blood, and ideally is bronchoalveolar lavage fluid BALF. Scientists believe there is a good correlation between total bacteria and endotoxin levels in bronchoalveolar lavage fluid.
Kupffer cells (KC) are damaged during liver disease, and endotoxin uptake and detoxification capacity are reduced. At the same time, due to the formation of internal and external portal vein shunts, hyperendotoxemia can be caused. Endotoxemia plays an important role in the prognosis of chronic liver insufficiency and liver failure. Both acute and chronic liver failure are mediated by endotoxemia, which works through direct toxicity and mediates cytokine production. Clinical monitoring of the level of endotoxin in the blood of patients with liver disease can be used to monitor liver function and disease development.
Bacterial meningitis is a dangerous disease, and early diagnosis is of great significance. Endotoxin in cerebrospinal fluid is relatively stable and is not cleared by endothelial cells. Endotoxin in the same shirt circulation cannot pass the blood-brain barrier. Some data indicate that the testing rate of cerebrospinal fluid endotoxin is as high as 90% for bacterial meningitis.
The pathogenic bacteria of urinary tract infections are mostly G-bacteria. The levels of endotoxin in normal urine and infected urine are very different, and the testing of urine endotoxin content is consistent with the results of bacterial culture of urine. It has important significance.
Creative BioMart offers a corresponding endotoxin detection service. You can purchase the corresponding endotoxin removal kit and related accessory products according to the needs of your own samples. We guarantee that all instruments, water, reagents, and consumables used in the experiment are free of endotoxins, and the experiment is conducted in a clean room to ensure that low levels of endotoxins are returned to the sample. In addition, we can also provide you with related services including:
|Project name||Endotoxin testing in body fluids|
|Testing purpose||The detection of endotoxin (ET) in body fluids can be used for early diagnosis of G-bacteria sepsis and endotoxemia, and has important clinical significance.|
|Testing cycle||3-5 days.|
|Service including||We provide you with raw data and test reports.|