Gel-Clot Limulus Amoebocyte Lysate Assay: A Method for Bacterial Endotoxin Detection in Nanoparticle Formulations

To perform a gel-clot LAL, prepare control standard endotoxin to a final concentration of 4 lambda, and combine 100 microliters of standard with 100 microliters of water, or test sample, to achieve a final concentration of control standard endotoxin 2 lambda.

Add 100 microliters of lysate to each lambda dilution. Vortex the tubes briefly, and place the rack of tubes into a 37-degree Celsius water bath for 1 hour.

At the end of the incubation, invert the tubes with a smooth motion, and manually record the results using plus for a firm clot, and minus for no clot or a loose clot.