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Cell survival curves have been obtained for Escherichia coli B (E. coli B) after the sonication of suspensions of the bacteria with continuous wave ultrasound at a fixed frequency of 2 MHZ between peak intensities of 8.7 and 2.25 W cm-2. It was found that under suitable conditions the survival curves were reproducible and it also was found that there was a clear relationship between the rate of inactivation and the peak acoustic intensity of the ultrasound. There appeared to be a lower threshold of peak intensity below which no inactivation was observed.

A time-resolved pulsed fluorescence immunometric assay (TR-PFIA) for carcinoembryonic antigen is described in which either Eu(III) or Tb(III) chelate is used as label. Described in detail is the assay involving the well-documented format of microtiter matrix and Eu(III) fluorescence enhanced with a beta-diketone and quantified in a commercial time-resolving fluorometer. We have also used the same basic assay, but one with a Tb(III) chelate as label, and we read the fluorescence signal directly off a surface without the application of enhancement solution. The Tb(III) fluorescence is then brought into solution by using an analog of dipicolinic acid in an enhancement solution. The latter approach demonstrates the scope of the methodology, which invokes the extra complexity of enhancement only when increased sensitivity might be required. The power and versatility of the enhancement methodology are demonstrated.