Comparison between automated optical and immunologic platelet counts

This graph depicts simultaneously-obtained automated platelet counts using an optical method (y-axis) and an immunologic method (anti-CD61, y-axis) for counts in the range from zero to 30,000 platelets/microL. The least squares best-fit line for the data points is shown as the red line, while the 95 percent confidence limits are shown by the two dashed blue lines. Note that the majority of the data points well outside of the 95 percent confidence limits are above the best-fit line, suggesting that the optical method is more prone to overestimate platelet counts than the immunologic method in this range.