This method validation protocol includes test requirements for endotoxin recovery in water using the ThermoMax Microplate Reader and SoftMax software. Specific objectives of this method validation are: --Verifying the labeled sensitivity of the kinetic turbidimetric Limulus amebocyte lysate, and to verity that the pyrogen-free LAL Reagent Water has no detectable level of endotoxing by comparison against a standard curve of certified Control Standard Endotoxin. --Determine the degree, if any, of inhibition or enhancement of the gel-clot reaction caused by samples from the water system; and, if present, the dilution at which inhibition/enhancement is overcome. --Validating the procedure that will be used for routine endotoxin determination on the water systems. References 21 CFR 210.13.b. See companion report, 09-0016-PVR-1.0.