ELISA Diagram: Assay Formats and Workflow

Choose the assay before drawing

An ELISA diagram explains how a plate-based immunoassay converts molecular binding into a measurable signal. The drawing should separate what is attached to the well, what arrives in solution, and what remains after washing. Choose the assay format before choosing symbols. A workflow overview emphasizes operations; a molecular close-up explains the binding arrangement. Combining these views in separate panels is clearer than squeezing every reagent into one well. State the analyte, sample type, and detection format in the caption so readers know what the final signal represents.

Three useful diagram variants

For a sandwich assay, distinguish the immobilized capture antibody, captured antigen, and detection antibody with a consistent legend. For direct detection, show an enzyme-labeled primary antibody binding the immobilized antigen. A competitive assay needs an explicit explanation of which species compete and which bound species produces the measured signal. Do not recycle a sandwich arrangement for competition. Use the three prompts above as starting points, then replace generic reagent names with the actual assay components. Keep standards and unknown samples in parallel lanes when explaining quantification.

Explain the experimental sequence

Number the operations from coating and blocking through sample binding, detection, washing, and measurement. Position wash arrows between the relevant binding stages rather than only at the end. Distinguish addition of a reagent from a molecular binding event: a pipette arrow means an operation, while a connector between antibody and antigen means an interaction. A final measurement panel can contain a schematic standard curve, but label invented values as illustrative. Incubation times, temperatures, dilution factors, and wavelengths must come from the specific protocol rather than a generic template.

Avoid misleading labels

Use separate colors or shapes for capture and detection antibodies, and identify the enzyme without implying it is present on every antibody. Check that the detection architecture matches the kit or protocol; not every format uses an enzyme-conjugated secondary antibody. Keep antibody binding sites facing the intended antigen and avoid drawing unsupported molecular detail. If a substrate reaction is enlarged, label that panel as a schematic. Check the legend at the final export size and explain abbreviations on first use. A useful figure caption states both what is measured and which experimental details were intentionally omitted.

Frequently asked questions