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... read more →
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Discussions and insights
on statistical issues in life sciences
Bioassay Blog
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... 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... 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... 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... 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... 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... 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... 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... 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... 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... 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 →
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 →
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... read more →
This blog explains the difference between true replicates and pseudo replicates, and discusses the problems that may arise if this difference is ignored or misunderstood in bioassay statistical analysis.... read more →
sim‧u‧la‧tion /ˌsɪmjəˈleɪʃən/ the activity of producing conditions which are similar to real ones, especially in order to test something, or the conditions that are produced.[i] In bioassay, simulation can be used during development stages and during assay maintenance, to supplement and... read more →
Correlates of protection in determining vaccine efficacy is a topic of particular interest, given the current COVID-19 climate and the spotlight on vaccine development. Here at Quantics, we have... read more →
✔ Cells looking nice and healthy in... read more →
It has been sometime since I have set foot in a lab, but the thought of seeing outliers in my data still sends a shiver down my spine –... 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... read more →
This is a quick blog outlining the difference between accuracy and precision and what this implies for assay development. It's simple stuff but often confusing. In the next blog we... read more →
At the recent BEBPA meeting, in response to the question: 'If you have a zero dose control on your plate do you include it in your 4PL model?' 78%... read more →