Tesina realitzada en col.laboració amb l'ICFO

Electrical charge is an indicator of the cellular state of health. The exact local charge can be determined only by a non-invasive technique. This project aims at setting a method for the determination of the overall electrical charge of a single living yeast cell by the optical trapping technique. The advantages of this method are the possibility of selecting the cells and the accuracy of the results. The experimental results were obtained from cell electrophoresis performed when the cell was trapped by an optical tweezers (OT), and in the absence of it. From the experiment carried out without the OT we report a mean charge of +165x10-17C for an average yeast cell of 5.7m diameter. The determination of the electrical charge for a cell trapped by an OT is possible with the development of the OT theory for inhomogeneous non-rigid objects