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on statistical issues in life sciences
Bioassay Blog
Software systems for calculating relative potencies and other bioanalytical results often provide a choice of variance estimation method, usually: Residuals, Lack of fit Error and Pure Error. This defines how... read more →
Interpolation analysis is used to find the concentration of a substance in a sample. For biologics, this is often used in ELISA analyses and other bioanalytic analyses. This blog... read more →
In our last blog we discussed the purpose of system suitability tests and sample suitability tests and gave some examples of each. However, we did not explain how to... read more →
Suitability tests for bioassay are often confusing. In this blog, we discuss the two types of suitability tests: System suitability tests and Sample suitability tests. The blog is deliberately simplistic... read more →
LD50 assays and challenge assays both measure the time to an event, often death, for each animal. However the standard statistical approach to the analysis of the data treats the... read more →
Welcome to our blog on combining relative potencies. In this blog, we’ll review the methods recommended by the United States Pharmacopeia (USP) and European Pharmacopoeia (PhEur) for combining relative potencies,... read more →
We can waste about 40% of multi-well plates to avoid biasing the relative potency (RP) due to “the edge effect”. Quantics recently used a Latin square design to support a... read more →
Our clients sometimes tell us that they don’t want to use response transformations since it feels like an unwarranted manipulation of the data. However, there is little point in avoiding... read more →
Many of our readers will be familiar with our paper “Parallelism in Practice” (PDA Journal of Pharmaceutical Science and Technology, 2015) and how we examined the common methods used for... read more →
Following the EurPh recommendations mixes up system and sample suitability and can lead to undesirable results. Assays failing when they should pass Assays passing when they should fail We recommend... read more →
Welcome to our fourth bioassay blog from Quantics Biostatistics. In our previous blog we discussed the 4 parameter logistic (4PL) model. This is a symmetrical S-shaped curve with the equation... read more →
As a slight change to our regular bioassay blog series where we last looked at the choice of statistical model when dealing with continuous response data. We thought we would... read more →
In the last blog we discussed the definition of relative potency and how it relates to the concepts of biological similarity and thus the need for parallelism between the reference... read more →
Relative potency is a term used in bioassay to refer to the ability of a test sample, of unknown potency, to produce the desired response compared to a reference sample,... read more →