Endotoxin is a complex of lipopolysaccharides (LPS) and proteins present in the outer membrane of all gram-negative bacteria. After the death of gram-negative bacteria cells, endotoxin is released to the environment. Injured intestinal mucosa allows access of the endotoxin to human blood, which causes endotoxemia, affecting the structure organs and cells, changing metabolic functions, and raising body temperature (Figure 1). Endotoxin can also access immune system through the liver circulation, which causes systemic inflammatory syndrome by improving the overexpression of various inflammatory cytokines. Besides, the high mortality rate associated with endotoxin-induced shock remains a major clinical problem.
Figure 1. Endotoxin access human blood resulting in endotoxemia with fever.
Endotoxin is not eliminated by the sterilization process when the microorganisms are killed. On the contrary, the release of endotoxin takes place upon the death of bacteria cells. Although the products may have been sterilized, the endotoxin mat still remains if gram-negative bacteria are present before sterilization. Therefore, endotoxin detection of the finished products is a critical part to ensure the biosafety of sterilized products, especially in the fields of biopharmaceuticals, biological products, food and water security, etc.
Endotoxin Detection at Creative Animodel
Creative Animodel provides endotoxin detection services to ensure the biosafety of sterilized products. The rabbit pyrogen test is the first standard technique for endotoxin detection. Nowadays, limulus amoebocyte lysate (LAL) test is the most popular detection method for endotoxin. With an in-depth understanding of endotoxin, biosensors are promising alternatives to develop fast-response, easy-operation, and low-cost endotoxin detection techniques. Creative Animodel provides all the techniques mentioned above to meet your different needs.LAL Test
It is found that the blood of the limulus polyphemus can form a clot in the presence of bacterial endotoxin. The reaction is caused by a clotting factor contained in motile blood cells called amoebocytes. Based on this unique property, the LAL test has been developed as the most popular endotoxin detection technique. There are several detection methods available based on LAL test, such as gel-clot, chromogenic, turbidimetric, and viscosity.Rabbit Pyrogen Test
The rabbit pyrogen test is an in vivo test to detect pyrogens qualitatively. Rabbits have a similar pyrogen tolerance to humans, so it is possible to determine the presence of pyrogens, such as endotoxin, by observing the change of body temperature in rabbits. Generally, the rabbit pyrogen test is applied as a supplement of LAL test in the endotoxin detection.Biosensors Test
Biosensors based on LPS affinity components are effective analytical devices that detect the presence of LPS by using a biological recognition element and then monitor the optical, electronic, mass, or magnetic signal variation that is induced by the interaction. Common biosensors include proteins, monoclonal antibodies, aptamers, and cells.
Creative Animodel has advanced technology platforms and experienced laboratory technicians for endotoxin detection. If you have any specific needs, please don’t hesitate to contact us. We look forward to assisting you with your project.
1. Su, W; Ding, X. Methods of Endotoxin Detection. Journal of Laboratory Automation. 2015, 20(4):354-64.