Mechanical force characterization in manipulating live cells with optical tweezers

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

78 Scopus Citations
View graph of relations



Original languageEnglish
Pages (from-to)741-746
Journal / PublicationJournal of Biomechanics
Issue number4
Publication statusPublished - 24 Feb 2011


Laser trapping with optical tweezers is a noninvasive manipulation technique and has received increasing attentions in biological applications. Understanding forces exerted on live cells is essential to cell biomechanical characterizations. Traditional numerical or experimental force measurement assumes live cells as ideal objects, ignoring their complicated inner structures and rough membranes. In this paper, we propose a new experimental method to calibrate the trapping and drag forces acted on live cells. Binding a micro polystyrene sphere to a live cell and moving the mixture with optical tweezers, we can obtain the drag force on the cell by subtracting the drag force on the sphere from the total drag force on the mixture, under the condition of extremely low Reynolds number. The trapping force on the cell is then obtained from the drag force when the cell is in force equilibrium state. Experiments on numerous live cells demonstrate the effectiveness of the proposed force calibration approach. © 2010 Elsevier Ltd.

Research Area(s)

  • Cell, Force calibration, Optical tweezers, Trapping force, Viscous drag force