We are all pretty familiar with COVID-19 lateral flow tests and home pregnancy tests. But lateral flow technology of course also allows the detection of many other diseases and conditions. And lateral flow technology is not limited to human health. Tests can detect pollutants in water, harmful toxins in foods, or zoonoses in livestock for example – the list is quite extensive.
Whatever your application for lateral flow technology, there are certain steps from our experience that we recommend you should follow. Abingdon’s R&D Director, Nina Garrett looks at these key considerations in developing for robust and reliable manufacturing.
Starting A Project: Specification is key!
Most lateral flow tests can be read visually but many can now be interpreted by a dedicated reader or Smart Phone App which expands the potential for data gathering and transmission for further analysis.
With this plethora of applications it is important when starting a lateral flow development program that key design specifications are defined at the outset. How will the test perform? How it will be interpreted by the end user? Which sample type will be used? What could be considered the final output of development will determine the inputs to the design in the early phases. Also, as outlined in other articles we have written, there also must be an eye on transferring the test into reliable and routine manufacture. Many considerations with multi-departmental input.
Developing for Manufacture: Some Key Considerations
The following outlines some key considerations that need to be confirmed at the start of a project to ensure that an efficient development program is designed to give the best possible outcome for the final test. Ultimately, you’re aiming for a rapid test that meets your customers’ expectations and can be produced robustly and efficiently.
What is the required performance of the test, what is the expected level of detection?
“This will drive the selection of the test line and conjugate particle /conjugate reagents to ensure that they are able to detect the target analyte over the required range.”
What is the sample matrix, and will it require a specific design solution e.g. filtration of large particulates, to ensure that a uniform sample matrix is added to the test? Does the sample need any dilution / manipulation to standardise the sample?
“Sample matrix requirements will confirm the need for specific sample pad selection and/or design of a test solution to work with the sample to ensure that the test runs to completion.”
Sample Collection and Addition To The Test
Does the sample need to be delivered in a certain volume? Is there a limitation to the available sample volume? How will the sample be collected?
“Sample collection and delivery to the test are key to the overall performance of lateral flow tests. When designing and testing in the laboratory the end user method of sample delivery should always be considered to ensure that the final test design can accommodate any expected variation in sample volume through the selected delivery method.”
Environment of Use
Where will the test be used e.g. in a laboratory, at home or in humid or arid conditions? Will there be risks of contamination to the test strip or damage due to the environment of use.
“Understanding of environment of use will confirm several design features and performance evaluation studies such as can the test strip be presented with or without a plastic housing to protect it and will covering the nitrocellulose be necessary to prevent potential damage. Also evaluating the test under in hot/ humid and cold/ arid conditions to confirm performance.”
Who will interpret the test and how will they interpret the results?
“Understanding the end user test interpretation method will impact the design of the test. If a reader such as mobile phone or bench top reader unit is being used to provide quantitative numerical result then the design specifications will be different from a qualitative visual test interpretation or by reference to a visual guide for a semi-quantitative test line signal interpretation.”
Every one of the steps above is designed to ensuring that the best and most appropriate test is developed in the most efficient time scale. All while making sure the test is in a good place to transfer and scale-up into routine manufacture.
At Abingdon Health we establish the key design requirements in collaboration with our customers to develop product requirement specifications. These specifications are the driver for test development so whether you are developing a lateral flow test for use in a clinical environment, on a farm, in an industrial environment or for use in the home (and yes we have experience with all of these settings and many more!) are the basis for successful development, scale up and transfer into manufacturing of the tests that we develop.
To see how we can take your test to the next level contact a member of our team.