Assays are highly diverse. And yet, there are some key aspects of assay development that stay the same across assays. When you're preparing to develop a new assay, here's a quick checklist for the process.
1. Specify molecule and state precisely what property of that molecule is to be tested
This is the foundation of assay development. Researchers may intend to measure a total amount of a specific substance, a distinct portion, or both. The parameters of the assay need to be determined, such as, whether the goal is to establish the amount of a substance, or its biological function. The assay must be designed to produce specific information about the molecule that is under examination.
2. Identify the molecule source
The source of the molecule often dictates the sample quantity and accessibility, and also is the determining factor for the concentration of the molecule in question. Source samples may be obtained from bodily fluids, biopsy sections, or cells cultured in vitro, which vary in availability. Researchers will be able to develop the assay workflow only after source factors are considered.
3. Determine the stability of the molecule during the course of the assay
Some molecules will require special precautions before samples can be collected and prepared for testing. Oxidation, enzyme activity, and other modifications may occur to the molecule as the assay progresses. Researchers need to ensure that the molecules retain their biologically relevant form, which may require reducing agents, or specific inhibitors. If the quality of the molecule is compromised, the assay data is irrelevant.
4. Determine number of samples included in assay
Some assays will be designed around a few samples that allow the researcher to develop an extremely comprehensive and complex assay. If large numbers of samples are to be assayed, hundreds or thousands, completing the assay may require streamlining efforts and introducing automated options.
5. Determine how the results will be measured
Clinical researchers must determine what measurement will be used to evaluate the assay process. Assay measurements may include:
- Qualitative, which typically only reports a pass or fail or a positive or negative.
- Semi-quantitative, which provide more graduations than a pass or fail and indicate results on a general scale.
- Quantitative measurements for researchers who require correct and exact numeric measurement of the substance being assayed.