The present invention includes {HEAD ~ a method} of detecting contamination in a fluid sample includes bringing a fluid sample into contact with a pair of spaced apart electrodes and applying {TAIL ~ a plurality} of voltages across the electrodes, wherein the plurality of voltages vary in magnitude between a first and second voltage level 
includes applying
The present invention includes { HEAD ~ a method } of detecting contamination in a fluid sample includes bringing a fluid sample into contact with a pair of spaced apart electrodes and applying { TAIL ~ a plurality } of voltages across the electrodes , wherein the plurality of voltages vary in magnitude between a first and second voltage level
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH