The earliest stages of the development of any vaccine involve laying out the roadmap for its design and testing. A vast network of interlinked paths from a new idea to a needle in a patient’s arm stretch ahead into the future, each with unique regulatory and ethical implications. Should the vaccine target a certain strain…
If you’ve ever taken a rapid test for COVID-19, then you’ve used an in vitro diagnostic device (IVD). At the start of the pandemic, the only reliable method for determining whether a patient was currently infected with COVID was a slow PCR test which required processing in a lab to return a result. By contrast,…
A bioassay supporting a commercial product often has a lifespan of several years or even decades. Over that time, it is often necessary that the assay be performed in a number of different laboratories for a variety of reasons. And, in each, the same rigorous standards must be held to ensure that the safety and…
Therapies based on monoclonal antibodies (mAbs) are among the most powerful medical technologies to have been developed in recent years. From treatments designed to attack cancer cells and prevent rejection following organ transplants to methods for treating infectious diseases such as anthrax and COVID-19, the applications for mAbs continue to grow. And that’s before uses…
Management of the reference standard over the life of a product is critical to ensuring consistent production of material. We always want to be able to draw a link between a new batch being produced and one that has demonstrated acceptable clinical properties, particularly safety and efficacy. That’s why reference bridging is so vital: it…
So, you’re confident that you’ve got a feasible assay with a well-defined dose-response curve. But bioassays, as we all know, are fickle. The observed responses are sensitive to many factors which can lead to appreciable variability in the experiment and, in turn, a high assay failure rate. An important part of the development phase of…
When scientific a study is evaluated, the sample size is often among the first issues brought up. Whether it’s the number of participants in a study, the number of times an experiment is run, or even the number of people asked to complete an electoral poll, it is well-known that – in general – a…
Vaccines are among the most important technological developments in human history. From the earliest attempts to prevent smallpox by variolation to modern mRNA vaccines built without a virus needing to have entered the development lab, the vaccine has become a vital string in the bow of public health officials. As with all medicines, batches of…
One of the most frequent topics of discussion on this blog has been the correct and optimal utilisation of different classes of statistical models with bioassay data. Most common among these are the four- and five-parameter (4 and 5PL) models, alongside the simple linear model. There is, however, stranger at the feast: the three-parameter logistic,…
Bioassays serve as a method of testing a product: does the latest batch of our biologic have an acceptable potency? To do this effectively, we need to ensure that our test system – the assay – continues to function as it was originally designed. This is crucial as, in the worst case, a flawed assay…
The control: a vital part of any scientific experiment. The only way to establish causality between the dependent and independent variables in an experiment is by comparison with a control. Controls are also important for establishing detection background: what does “nothing” look like on your sensor? Bioassays are no different: including control wells in your…
The idiom “to pull oneself up by their bootstraps” originated in the late 19th century. At first, it implied impossibility, but has since shifted to mean advances achieved through grit, determination, and hard work, often in business or in one’s career. Thankfully, the statistical method – bootstrapping – named for the idiom rarely requires such…
In bioassay analyses, there are three statistical models that are commonly fit to dose-response data: the linear model, the 4PL model, and the 5PL model. We’ve examined the properties of the 4PL model in great detail previously, and the time has come to give the 5PL model a similar treatment. The 5PL model is the…
Enzyme-Linked Immunosorbent Assays (ELISA) are a key tool for determining concentrations, forming a key component of many fields in the life sciences. From testing food products for allergens to detecting HIV in a patient’s blood and beyond, ELISA analysis is a vital component of a scientist’s arsenal. Quantics has been at the forefront of research…
When running a bioassay, we face a constant battle between two competing requirements. The assay must be able to detect when something has gone wrong with the experiment or the product, but, simultaneously, must not be so sensitive that the assay fails frequently due to the natural variability of the biology at play in a…
The Organisation for Economic Co-operation and Development (OECD) is an inter-governmental organisation which aims to facilitate global trade and economic development. A key area is the development of global standards. The OECD’s Good Laboratory Practice (GLP) scheme is an example of such standards: It provides guidance on all aspects related to non-clinical health and environmental…
At the forefront of medical development lies the world of cell and gene therapy. Unlike traditional, small molecule therapeutics, treatments based on biologics can treat, cure, or even prevent genetic conditions such as sickle cell anaemia and muscular dystrophy. They can also be tailored to individual patients, giving the potential for personalised treatments for certain…
Statistics is divided between two camps: the frequentists and the Bayesians. The latter of these has begun to attract more popular attention in recent years with the rise of AI and other similar technologies. This has extended to the life sciences, in which there are several fields where Bayesian approaches are taking centre stage. So,…
A concept we’ve discussed several times over the years is that of homogeneity of variance. We highlight it so regularly as it’s among the most critical properties that relative potency data must have before valid statistical inference can take place, and often requires careful consideration to realise. We’ve previously covered one common way to ensure…
In previous blogs, we’ve examined the statistics behind Non-Compartmental PK/PD analysis. The existence of the Non-Compartmental Analysis (NCA) implies the existence of compartmental analysis, and, indeed, it is among the most commonly used methodologies for PK/PD statistics. Rather than extract results from data alone as in an NCA, a compartmental analysis involves fitting a model…