How to Download and Use the EPA Probit Analysis Program for Bioassay Data
How to Download and Use the EPA Probit Analysis Program for Bioassay Data
Probit analysis is a statistical method that can be used to analyze data from bioassay studies, such as determining the effects of insecticides on insect mortality. The EPA Probit Analysis Program is a software tool that can perform probit analysis using different transformations of the data, such as probit, logit, complementary log-log, and others. The program can also provide information for reporting the results of probit analysis, such as slopes, intercepts, confidence intervals, and goodness-of-fit tests.
Epa probit analysis program free download
In this article, we will explain how to download and use the EPA Probit Analysis Program for bioassay data. We will also provide some examples of how to interpret the output of the program.
Downloading the EPA Probit Analysis Program
The EPA Probit Analysis Program is written in the Mathematica language. You must have the Wolfram Mathematica or Wolfram Player Pro software on your computer to run this program. You can check if you have free access to Mathematica by visiting the Mathematica web site (www.wolfram.com) and the web site will automatically notify you if you have a site license. If you don't have a site license, you can purchase the Player Pro software package, which is more economical than Mathematica and will allow you to run programs written in the Mathematica language.
To download the EPA Probit Analysis Program, follow these steps:
Go to this link [^2^] and click on "Time-mortality programs - tmprogs.zip". This will download a zip file containing two programs: PROBIT and PROBIT2.
Extract the zip file to your Documents folder (this is the default directory where Mathematica looks for files), and then delete the zip file.
The programs are ready to run in Mathematica or Player Pro.
Using the EPA Probit Analysis Program
The EPA Probit Analysis Program can be used to analyze bioassay data when multiple observations over time were made on the same groups of organisms at one dose of a stimulus. For example, you treated one batch of 100 insects with one dose of an insecticide, and then checked mortality of that one batch of insects at 24, 48, 72, 96, and 120 h.
The program PROBIT can perform probit analysis using one of six possible transformations of the data: probit, logit, complementary log-log (CLL), log-probit, log-logit, or log-CLL. You can choose which transformation to use by entering it in the input box. The program PROBIT2 can perform probit analysis using all six transformations at one time.
To use the EPA Probit Analysis Program, follow these steps:
Open Mathematica or Player Pro and go to File > Open. Navigate to your Documents folder and select either PROBIT or PROBIT2.
A notebook will open with instructions on how to enter your data. You can enter your data either by typing it directly into the notebook or by importing it from a text file.
After entering your data, click on Evaluation > Evaluate Notebook. The program will run and display the output in the notebook.
You can save or print the output as you wish.
Interpreting the Output of the EPA Probit Analysis Program
The output of the EPA Probit Analysis Program will provide you with information for reporting the results of probit analysis, such as:
The slopes and intercepts of the regression lines, with their variances and covariance.
The chi-square for goodness-of-fit of the regression line.
The lethal time values (LT50, LT90, etc.), with confidence limits.
The graphs of observed and predicted proportion organisms responding at each time or dose.
You can use this information to compare the effects of different stimuli on different organisms, or to test hypotheses about the mechanisms of action of stimuli. For example, you can compare the slopes of different regression lines to see if they differ significantly, or you e0e6b7cb5c