Drug molecules detection

Buehler, C., Stoeckli, K. and Auer, M. (2001). The integration of single molecule detection technologies into miniturized drug screening Current status and future perspectives. In New Trends in Fluorescence Spectroscopy (Valeur, B. and Brochon, J. C., eds.). Springer, Berlin, pp. 331-79. 

Immunoassay is the sterile measurement of a drug molecule as an antigen using a specific antibody. Detection is performed by UV light absorption, radioactivity, or fluorescence polarization. 

Smaller diameter probes reduce sample volumes from 500 to 600 pi typical with a 5 mm probe down to 120-160 pi with a 3 mm tube. By reducing the sample volume, the relative concentration of the sample can be correspondingly increased for non-solubility limited samples. This dramatically reduces data acquisition times when more abundant samples are available or sample quantity requirements when dealing with scarce samples. At present, the smallest commercially available NMR tubes have a diameter of 1.0 mm and allow the acquisition of heteronuclear shift correlation experiments on samples as small as 1 pg of material, for example in the case of the small drug molecule, ibu-profen [5]. In addition to conventional tube-based NMR probes, there are also a number of other types of small volume NMR probes and flow probes commercially available [6]. Here again, the primary application of these probes is the reduction of sample requirements to facilitate the structural characterization of mass limited samples. Overall, many probe options are available to optimize the NMR hardware configuration for the type and amount of sample, its solubility, the nucleus to be detected as well as the type and number of experiments to be run. 

Furthermore, novel methods for single molecule detection will contribute to improved drug discovery. For instance, fluorescence correlation spectroscopy (FCS) is characterized by the ability to measure single molecules in sub-micro liter sample volumes with a typical range of sensitivity between 10 6 and... 

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