In Situ Quantification of the Young’s Modulus of Nuclei In Multiple Cellular States Using A Modified Fiber Probe Sensor

摘要： In this work, a modified fiber probe sensor (MFP sensor) with a considerable length-diameter ratio tip was developed to quantitatively characterize the Young’s modulus of the cell nucleus in multiple cellular states. The MFP sensor has a needle tip with an extended length of 30 μm and a diameter of 150 nm. The length of the tip exceeds the diameter of most cells, so that it can penetrate the cell membrane with minimal damage and reach the nucleus. This allows the measurement of the Young’s modulus of intact cell nuclei under different cellular states without the phenomenon that the cantilever contacts the cell membrane. Moreover, the stiffness of the MFP sensor is reduced by a factor of 25 to better match that of the cell membrane and nucleus, which enables high-precision mechanical measurements. The MFP sensor was successfully used to quantify the Young’s modulus of the intact cell nuclei in the non-adherent, adherent and early apoptotic states. Experimental results validated the capability and versatility of the developed method.