Figure 5. Rotational bias of cells placed in constant magnetic fields.
A) Average angular velocity of cells as a function of their initial orientation, plotted for magnetic fields with different magnitudes (mean ± standard error). Fit was performed according to the rotational bias model (Eq. 9). B) Ratio of magnetic torque to rotational drag coefficient for cells placed in magnetic fields of various magnitudes. Plotted values are obtained from fit of data such as those shown in panel A. Linear fit to the data measured at magnetic fields B<2 mT yields a magnetic moment μ = 5.7±0.2×10−16 A⋅m2, as explained in the text.