How to use probit table?

With both the probits and the log of the concentrations calculated, the next step is to plot them against each other and fit a line of regression. This line represents the best fit through the data points, providing a visual representation of the relationship between the probits and the concentrations.

Once the regression line is established, the next objective is to find the LC50, or the concentration that causes 50% mortality. This value is determined by interpolating the regression line at the probit value corresponding to 50% mortality. The LC50 is a crucial metric in toxicology, as it provides a measure of the toxicity of a substance.

The process begins by transforming the percentage mortality data into probits, which serve as a quantitative measure of the probability of death. This conversion step is crucial for statistical analysis, as it standardizes the mortality data into a more manageable and interpretable format.

In addition to the LC50, it is also important to determine the 95% confidence intervals for this value. The confidence intervals provide a range within which the true LC50 is likely to fall, taking into account the uncertainty inherent in the experimental data. This step ensures that the LC50 estimate is both precise and reliable.

Following the conversion, the next step involves taking the logarithm of the concentrations used in the experiment. This logarithmic transformation helps to linearize the relationship between the probits and the concentrations, making it easier to identify trends and patterns within the data.