It is a basic premise of scientific publishing that findings reported in a paper be reproducible. This necessitates the sharing of unique reagents, as well as the adequate documentation of the methods used. We have outlined our updated policies on sharing materials in the March 2005 editorial and last month on Nature's extended online methods. Laudably, the ISSCR (see above) recently published strict guidelines for sharing human ES cell materials and data, which will hopefully help reinvigorate this essential aspect of research cultureFootnote 1.

One of the most frequent problems regarding experimental transparency has been the release of commercial RNAi probe sequences. Testament to this are the five addenda in the last two issues of Nature Cell Biology providing the delayed release of RNAi sequences. In our view, a researcher has to be aware of the sequence of a probe used to be certain of its specificity. A company's assurances of specificity are of limited value, as the context of the experiment may be quite different to the company's own quality assessment. A case in point is a paper that Nature Cell Biology published in 2005: when the commercial RNAi probe sequence was finally obtained after publication, it turned out that the probe was predicted to have an unexpected second target (Nature Cell Biol. 7, 311–318; 2005). Aside from the 'black box' issue, it is also not sufficient to list a catalogue number, as a company may change or discontinue a product at any time.

We understand that these reagents are often produced by small biotechs in a competitive environment and that the published sequence may facilitate copying. We also appreciate that patent protection can take too long to be effective in this fast moving field. However, if this leads to restrictions on information that undermine the scientific process, researchers ultimately should look elsewhere for their reagents. In our opinion, it is unlikely that revenue would be lost on a keenly priced product; after all many easily copied or self-manufactured laboratory products not protected by trade secrets, such as precast gels or DNA purification kits, sell well.

Undoubtedly, there can be exceptional circumstances: a genome wide RNAi library will have incurred significant R&D costs. In a case such as this, we would only expect release of the sequences of the most relevant hits identified. There is a case to be made for certain chemical modifications to RNAi probes (for example, to reduce off-target effects) to remain proprietary until covered by patents. At present, we have not enforced the release of control probes, which remain more tightly guarded by some companies to protect 'best sellers', although the release is to be strongly encouraged. To clarify our publication policy, our 'Guide to Authors' now states “The sequences of all RNAi, antisense and morpholino probes must be included in the paper.... When an unpublished library is included...the sequences of probes central to the conclusions of the paper must be presented.” (http://www.nature.com/authors/editorial_policies/availability.html)

It is encouraging to see that more far-sighted companies are beginning to open up their sequences — in the case of Dharmacon, as a matter of course, since early spring. We encourage the community to take transparency into account when choosing their reagent provider.