A method of using a mixture as an amphoteric buffer is disclosed comprising mixing sulfuric acid, magnesium oxide andor magnesium hydroxide, and water to form an amphoteric buffer, and applying the buffer to a spill of an acid or alkali so as to neutralize the spill. Reduced temperatures prevent popping of the photoresist which can cause particulate contamination. In a standby mode in which the lamp turn-on permission signal is not detected, operation of a PFC control unit provided in the power-factor improving circuit is stopped. A sensor in communication with the hydrophilic region is used to determine the amount of product produced or the amount of excess oxygen present allowing for the concentration of the biomolecule to be determined.