A test example for LDs ) determination for thymoquinone administered intraperitoneally in rats, demonstrates the implementation of interactive computer programs for computing LDso and other LD values using Finney method (Program 'LDsomortality- Finney') and Miller-Tainter method (Program 'LDsomortality- Miller-Tainter'), written in MATLAB. Detailed program algorithms and their execution, as well as the differences between them, resulting from differences between the methods, are presented. The Finney method transforms results obtained for mortality (in %) to probit values, where probit values for 0% and 100% mortality depend on the number of experimental animals in the group, and then continues processing. The Miller-Tainter method also transforms mortality results (in %) to probit values, but previously

corrects percentage values, relevant to the number of experimental animals, if mortality for the lowest dose is 0% and for the highest dose 100%, the corrected values are changed to probit values, and then continues processesing. In the case of O0ECD Modifications 420, 423 and 425, once the doses for the determination of LD) and other LD values are chosen, Litchfield-Wilcoxon statistical program is usually used to estimate these values and their confidence limits. In the test example of thymoquinone given intraperitoneally to rats LDo, LDi., LDs0, LDga and LD 190 values obtained by applying the programs “LDsomortality- Finney”, “LDso-mortality-Miller-Tainter” and those calculated by Litchfield-Wilcoxon method were very similar and Fischer's coefficient (F) value showed no statistically significant differences between them (P>0.05).