There are three key elements to manufacturing lateral flow assays that enable consistently accurate and reproducible results:
Expertise ensures that an assay is optimised and scaled-up efficiently for routine manufacturing; experience means tried and tested processes and procedures are utilised, regulatory considerations are taken into account, and market requirements are established and adhered to; and automation ensures that the devices developed and manufactured provide accurate results time and time again, with excellent inter and intra-batch reproducibility.
Once an assay has progressed through the feasibility and optimisation phases of an assay development project, scale-up to manufacture is the next process prior to routine manufacture. This is where the manufacturing specifications are set in order to manage large batch sizes.
Lateral flow assays can be manufactured and assembled by hand; however, the cost implications, batch sizes and assay reproducibility of this manual process can drive the decision to switch to automation.
At Abingdon Health we use the following automated lateral flow manufacturing equipment to ensure assay accuracy and reproducibility:
Contact and non-contact tips for dispensing
Equipment is set-up to dispense in accordance with preset parameters devised by assay specialists during development.
Extensive testing during development will dictate which method will be utilised to ensure robustness and reproducibility.
Reel-to-reel web handling system for reagent spraying
Precise deposition of reagents onto the nitrocellulose membrane and conjugate release pad is essential for accurate results, particularly in the case of quantitative assays. Without this highly precise equipment, the assay performance could be compromised and fail to achieve the required specifications.
Abingdon Health’s reel-to-reel system allows up to 5 lines to be sprayed simultaneously, reducing the amount of handling of the membrane. Drying towers ensure constant conditions are maintained for the complete length of the sprayed materials, contributing to assay reproducibility.
Auto-laminator for assembly of membranes and other components
Once membranes and conjugate release pads have been sprayed with the necessary reagents they need to be applied to a backing card. During this process reels of membrane, conjugate pad, wicking pads and other assay components are laid sequentially onto a reel of backing card. The alignment of these materials is critical to the functionality of the assay and using dedicated equipment such as the auto-laminator ensures reproducibility and minimises batch failure.
Automated dispensing of buffers
For some applications the use of a precise volume of buffer, whether a dilution buffer or a chase buffer, is essential to the assay design. The ability to dispense multiple batches of a buffer using automation ensures accuracy and removes the potential issue of user error.