*5.4. Endotoxin Contents Determination*

Samples of BaV (20 μg/mL) and Kn-Ba (1 μg/mL) were diluted in sterile PBS, pH 7.2, and the endotoxin presence was analyzed by the Microbiological Quality Control of Butantan Foundation using the PYROGENT TM Gel clot LAL Assays kit (Lonza, Walkersville, MD, USA), according to manufacture instructions. Endotoxin concentration was estimated by comparing with an *Escherichia coli* LPS standard (0.125 UE/mL).
