Published online May 12, 2016. doi: 10.5501/wjv.v5.i2.85
Peer-review started: January 10, 2016
First decision: March 1, 2016
Revised: March 2, 2016
Accepted: March 17, 2016
Article in press: March 19, 2016
Published online: May 12, 2016
Two commonly used methods for calculating 50% endpoint using serial dilutions are Spearman-Karber method and Reed and Muench method. To understand/apply the above formulas, moderate statistical/mathematical skills are necessary. In this paper, a simple formula/method for calculating 50% endpoints has been proposed. The formula yields essentially similar results as those of the Spearman-Karber method. The formula has been rigorously evaluated with several samples.
Core tip: The formula described in this manuscript can be used to calculate 50% endpoint titre such as TCID50%, LD50, TD50, etc., in addition to the currently existing methods. The proposed formula can be applied without the help of calculator or computer.