Pharmaceutical applications of photothermal cytometry

We describe two optical methods for in vitro drug trials on living cells and cell cultures. Response of each single target cell to drug impact is measured as the change of cell functional and structural state by photothermal (PT) imaging and the changes of cell viability is controlled with Laser Viability Test Both photothermal methods are sensitive to specific cell reaction but although to reaction of general origin. High sensitivity of the methods allows to use minor amounts of drug and cell materials (microliters). Pharmaceutical applications are illustrated with the results of in vitro experiments being obtained for human living blood cells: 1.Fast evaluation of drug impact (within the minutes after drug injection) on structural and functional condition of single living cell; 2. Control of drug quality and therapeutic regime by cell population screening, 3. Dose evaluation and comparison of several drugs at cell level; 4. Evaluation of toxic and therapeutically efficient doses; 4. Control at a cell level of mechanism of drug action; 5. Trial procedure standardization though the use of reference cell cultures. Technically photothermal methods are compatible with optical microscopy and flow cytometry. Photothermal microscope for automated analysis and monitoring of living cell samples is described.