Bacterial endotoxins are lipopolysaccharides (LPS) generally found in the outer membrane of gram-negative bacteria, such as E.coli, and are widely present in our environment. Because of the pyrogenic nature of endotoxins, with human effects from fever to hemorrhagic stroke, FDA regulations require that raw materials (e.g. water) used in parenteral drugs be tested for endotoxin levels. Available microplate-based Limulus Amoebocyte Lysate (LAL) test protocols for endotoxins include both turbidimetric and chromogenic method of detection. Some protocols follow temperature-controlled kinetic processes and are typically performed in a microplate reader. Data analysis can include a standard curve for quantitation of sample concentrations, kinetic rate of reaction, Onset time (the time it takes each well to reach a specified Onset OD), and % recovery (the total amount of endotoxin recovered from “spiked” wells), along with LAL-kit specific parameters.
Consistent temperature control over time is critical to these kinetic assays, and the Agilent BioTek ELx808 Absorbance Reader is a proven performer with these temperature sensitive assays.
- 4-Zone temperature control
- 340 nm to 900 nm wavelength range
- Fast kinetics, endpoint and linear well scanning read modes
- Validated for use with commercially available LAL tests