Curve fitting approach for measurement of cellular osmotic properties by the electrical sensing zone method. I. Osmotically inactive volume

摘要: We have investigated the confounding effects of dynamic range limitations on measurement osmotically inactive volume using electrical sensing zone instruments (e.g., Coulter counters), and propose an improved approach to parameter estimation. The conventional for analysis cell size distributions measured by such particle sizing requires data truncation: mean is computed after exclusion below a specified lower bound (typically chosen remove artifacts due small-volume noise) above upper governed instrument limitations). then estimated from Boyle-van't Hoff plot averaged obtained exposure various solution osmolalities. demonstrate that systematic in introduces bias results erroneously high estimates fraction. To minimize this source error, we devised new algorithm based fitting bimodal distribution model non-truncated data. In experiments with mouse insulinoma (MIN6) cells, fraction was be 0.15+/-0.01 method, which significantly smaller than estimate 0.37+/-0.02 method (p<0.05). silico indicated accurate within 5%, whereas error associated approximately 150%. Parametric used elucidate sensitivity errors variations width.