Sir

Your News Feature 'The hard copy' (Nature 446, 485–486; 2007) accurately highlights the limited availability of information on stem-cell research methodologies — owing to competition among labs, the commercial value of such information and space restrictions in high-quality journals — which contributes to other labs' inability to replicate and verify the results.

It might sometimes repay scientists to look beyond conventional journals for information, in this or other disciplines, particularly to patents or patent applications. Thanks to the strict enablement requirements of patent law and patent offices in relation to inventions, one can often find more detailed methodology in patent documents than in journals with severe page limits.

A very good example of comprehensive detail in certain non-embryonic stem-cell methodologies is a PCT application WO/2006/028723 (Non-Embryonic Totipotent Blastomer-Like Stem Cells and Methods Therefor), which includes surgical procedures in organ removal, isolation of cells, and composition and preparation of culture media. In this instance, the level of detail and volume of text relating to methodology far exceeds that which many peer-reviewed journals can accommodate.

Some journals publish methodology and protocols online as Supplementary Information to the main paper or in separate publications (an example is Nature Protocols, which encourages user comments). Often, though, journals are only starting points in complex paper trails related to methods. In these circumstances, patent documents could contain the most methodology related to an invention in a single document.