Endotoxin Protocol

Endotoxins are small, bacterial molecules. They are typically found on laboratory equipment and chemical materials. Their presence contaminates lab cell cultures, experiment results and medications for internal use and may cause fever in humans. Laboratory protocols aim to prevent endotoxin contamination.

Contamination

• Lab materials such as chemical reagents and buffers are an endotoxin source. These should be tested for endotoxins using the Food and Drug Administration (FDA) bacterial endotoxin test.

  Water is another source of endotoxins. Distillation is an effective method of removing the contaminants. People's hands are another source; therefore, latex gloves should be worn when handling both water and lab equipment.

Cleaning Laboratory Equipment

• As endotoxins remain stable when exposed to high temperatures, the normal sterilizing methods do not work. Endotoxins are also hydrophobic. This means the molecules are attracted to the surface of other hydrophobic materials, such as plastic, which a lot of laboratory equipment is made from. The FDA recommends using dry heat sterilization at high temperatures. Research shows that heating glass equipment at 250 degrees C for 45 minutes is effective.

Endotoxin Levels

• It is not possible to remove all endotoxins during the drug-manufacture process. Manufacturers must test drugs for endotoxin levels, and these must conform to FDA guidelines. For example, sterile water has a limit of 0.25 Endotoxin Units (EU), and cyancobalamin injections (Vitamin B12) have a limit of 350EU per milliliter (ml) of the product.