The Dichotomous Assay Package provides an update of the dichotomous assay document type. This document type allows you to analyze biological dilution assays based on a binary (quantal) outcome. Fit probit and logit models to the probability distributions of your sample data and compare them to the reference standard. The results include absolute/relative potency estimates, sample recovery estimates, and the half-maximal effective concentration (EC50) of samples. Configure suitability tests on the calculated parameters to prove the validity of the assay. The dashboard and reports are presented in a modern and more informative look. The dichotomous assay document type also supports the full functionality of the attachments editor, introduced with PLA 3.0.6.

Features of the Dichotomous Assay Package

  • Potency calculation of assay data with binary (quantal) outcomes
  • Probit and logit regression models to fit sample data
  • Half-maximal effective concentration (EC50) calculation
  • Suitability tests for the calculated parameters
  • Full functionality of the Attachments editor

Basic concept of the Dichotomous Assay Package

The Dichotomous Assay Package allows you to analyze biological assays with binary (quantal) outcomes by applying either the probit or logit model to estimate the potency of your samples. To support you in setting up these assays, it provides the Dichotomous assay document type, previously a part of the Biological Assay Package. You can also define suitability tests to prove the validity of the assay. In addition, the document type was improved in several aspects. The definition of dose steps includes a new option to specify a dilution sequence. The Dashboard and reports are presented in a modern and more informative look. For example, observe regression results already on the Dashboard, and switch between probability-based plots and their linear transformation. Reports now also include half-maximal effective concentration (EC50) and sample recovery estimation.

Use cases of the Dichotomous Assay Package

The Dichotomous Assay Package can be used to analyze assays based on binary responses (in contrast to quantitiative or continuous responses). For example, the physical reaction by cells or organisms to a substance can be classified as a 'yes' or 'no' response. In a dilution sequence of the substance, more cells or organisms typically show a reaction at higher doses. This leads to a probability distribution at every step. The Dichotomous assay document type provides you with tools to document, prepare, and analyze your assay data. Preserve assay information in the document and attach external files to the document to keep all relevant information in one place. Develop your analytical method by choosing between probit and logit models, and fine-tune statistical settings. Prove the validity of your assay with a large set of configurable tests on the calculated values. For example, you can specify margins of the values and which type of samples (reference, test, control) should be affected. After calculation, the Dashboard provides a first look at the results, including potency estimation for the test samples, and an overview of the regression and suitability tests. You can also generate reports which contain detailed information about the assay setup and analysis, such as the half-maximal effective concentration (EC50).

Example of an Sample Report for a dichotomous assay

  • Sample Report for a dichotomous assay 114 KB
    Example taken from 'Statistical Method in Biological Assay' by D.J. Finney, 3rd Edition, 1978, Griffin. Data as given on page 376. Calculated potency and 95% confidence limits are in agreement with the computer-print on page 387.