An easy and fast gel diffusion assay for detecting and monitoring lipase activity by quantification of fluorescein is described. By measuring the intensity of fluorescein, it is possible to obtain a calibration curve with a regression coefficient better than by using the radius of fluorescent haloes. Through the quantification of fluorescence intensity of fluorescein released after the hydrolys...

The most common method for quantifying small-molecule drugs in blood samples is by liquid chromatography in combination with mass spectrometry. Few immuno-based assays are available for the detection of small-molecule drugs in blood. Here we report on a homogeneous assay that enables detection of the concentration of digoxin spiked into in a plasma sample. The assay is based on a shift in the e...

4 Luminescence-based assay methods in drug discovery

A facile and sensitive aptamer-based protocol has been developed for protein assay on microfluidic platform with fluorescence detection using an off-chip microarray scanner. Aptamer-functionalized magnetic beads were used to capture thrombin that binds to a second aptamer fluorescently labeled by Cy3. Experimental conditions, such as incubation time and temperature, washing time, interfering pr...