RAPID DETECTION OF ESCHERICHIA COLIFORM USING A SERIES ELECTRODE PIEZOELECTRIC CRYSTAL SENSOR

A series electrode piezoelectric crystal sensor was used to determine Escherichia coliform (E. coli.). This method is simple and rapid, and requires only a single sample dilution. E. coli. in the range of 10 - 10(6) cells per mi can be estimated by this method. The procedure is a frequency detection time (FDT) method. The factors which affect the determination are discussed. Thirty samples in pure culture were tested by this method and the results fell within the 95% confidence limits of the standard plate count values. A correlation coefficient of 0.93 was obtained between the frequency detection time and logarithm of initial bacterial concentration. This corresponds to the criteria used to evaluate E. coli. with the added advantage of single dilution and more rapid results.