01Describe the material the experiment used

Start with the name and a sufficiently specific molecular description. Where needed, include sequence, modifications, declared form or defined blend components. The level of detail should resolve the distinctions that matter to interpreting the experiment, rather than relying on an ambiguous trade name.

Record the supplier, catalogue identifier where available and lot or batch reference. If multiple lots were used, identify their relationship to the experiments. A single generic source statement can hide a material change between runs.

Nature's chemical-characterisation guidance asks for enough experimental and characterisation information to reproduce reported work. Its detailed requirements concern particular publication contexts, but the general reporting aim is relevant here: a reader needs to know what the material description and evidence actually establish.Nature characterisation guidance (opens in a new tab)

02Separate three kinds of quantity statement

For an original writing example, “vials labelled 10 mg” and “the supplier report stated 9.98 mg per vial” are different statements. Neither should be rewritten as a measurement made by the study team unless that measurement actually occurred. If a value informed a calculation, identify which value and why.

The same rule applies to purity. Give the reported basis and relevant method rather than dropping a bare percentage into the text. Readers need to know whether the value refers to chromatographic area, an assay or another defined quantity.

03Connect characterisation to the samples used

Identify the report or dataset supporting the material description, including the applicable lot and version where available. If the study performed additional identity or quality checks, describe them separately from the supplier documentation. Avoid merging two evidence sources into an unnamed overall assurance.

If characterisation applied to a sampled vial or bulk material, preserve that sampling scope. Do not report that every experimental vial was tested when the available record describes one submitted sample. A methods section is a place to state the limits of the record clearly.

04Retain the details that a changing web page cannot

A live product URL can be helpful, but it is not an archive of the exact description available when the study was performed. Retain the relevant certificate, specification version and dated records in the study's documentation. Use a suitable persistent data location where sharing is appropriate and permitted.

Nature Communications' reporting policy emphasises access to the data, materials and protocols needed to interpret and build on published claims, and disclosure of availability restrictions. Follow the actual journal and institutional requirements for your work rather than assuming a supplier link satisfies them.Nature reporting policy (opens in a new tab)

Describe experimental handling and quantities from the records of what was done. Do not fill missing methods with generic instructions copied from a supplier or another paper. If a published procedure was followed, cite it and identify relevant departures.

05Check the final paragraph against the source records

• ✓Can the reader distinguish the exact entity from similarly named materials?
• ✓Are supplier, product identifier and lot recorded where available?
• ✓Are label claims and analytical results clearly attributed?
• ✓Are characterisation methods and sampling scope described accurately?
• ✓Are relevant records accessible or their restrictions explained?
• ✓Does the experimental description reflect what was actually done?

This checklist does not guarantee reproducibility by itself. It makes the reagent's contribution to the experimental record inspectable. The remaining methods, design, analysis and data must provide the rest of the context needed to interpret the study.