Papers Published

  1. Hochmuth, R.M. and Needham, D., The viscosity of neutrophils and their transit times through small pores, Biorheology (UK), vol. 27 no. 6 (1990), pp. 817 - 28 .
    (last updated on 2007/04/10)

    Passive neutrophils from five different individuals are rapidly aspirated at constant suction pressure and at room temperature into a pipet with a diameter of 4 μm. The excess suction pressures (i.e. the pressures in excess of the small threshold pressure required to produce continuous flow into the pipet) are 5000, 10000 and 20000 dyn/cm2 (0.5, 1 and 2 kPa) and are comparable to those encountered in the microcirculation. The rate of entry into the pipet is modeled with a linearized version of a theory by Yeung and Evans for the Newtonian flow of a neutrophil into a pipet or pore. From this theory and measurements of the cell size and its rate of entry into the pipet, the authors can calculate a value for the cytoplasmic viscosity. A linear (Newtonian) fit of the theory to the experimental data gives a value for the viscosity of 1050 poise. A non-linear fit predicts a decrease in the `apparent viscosity' from about 1500 poise at zero excess pressure to 1000 poise at an excess aspiration pressure of 20,000 dyn/cm2

    biorheology;blood;cellular transport and dynamics;viscosity;