Digital image guidelines

The ethical guidelines for the Society for Endocrinology journals comprise an Author Code of Ethics, of which the two first points are:

  1. Authors must present an accurate account of research performed as well as an objective discussion of its significance.
  2. Authors must accurately represent underlying data in the paper.

In view of the above, and recognizing that the inappropriate use of computer software for digital image analysis and processing can raise concerns, the Editorial Board have decided to provide more detailed requirements for the representation of research data, in particular digital images that that result from gel electrophoresis and blotting procedures:

  1. Band intensity should be quantified from several independent experiments. If only a "typical" experiment is shown in the figure, authors should be prepared to provide unprocessed images of gels or blots for review purposes if requested, and they may be asked to provide these as supplementary material to an accepted manuscript.
  2. The legend to a digital image should state if and what digital modifications were applied.
  3. Digital image processing is acceptable only to enhance clarity of presentation, not to obscure multiple bands or "bands of no interest". Digital enhancement should apply to the entire image, not just selected bands or lanes. Avoid extreme-high-contrast images, gels and blots can have a grey background.
  4. Extensively cropped images are not acceptable. Images can be cropped to enhance clarity of presentation, but should always contain at least two markers (one with a smaller, one with a larger molecular size than the band of interest) with their molecular sizes indicated.
  5. Producing spliced images by combining lanes from gels or blots from different experimental runs should be avoided. A lane containing markers should be on the same gel for each run. If spliced images are presented, the vertical lanes obtained from gels or blots from different experimental runs should be clearly demarcated with lines.
  6. As the validity of immunoblots relies heavily on antibody specificity, an appropriate control (tissue from knockout mice or protein knockdown in cell lines) must be included, or alternatively a reference should be given in the methods section referring to such a control (Saper 2009; Burry 2011).
  7. The reuse of images of loading controls from other experiments or previous publications is clearly unacceptable.

References

  1. Burry RW 2011 Controls for immunocytochemistry: An update. Journal of Histochemistry & Cytochemistry 59 6–12. (doi:10.1369/jhc.2010.956920)
  2. Saper CB 2009 A guide to the perplexed on the specificity of antibodies. Journal of Histochemistry & Cytochemistry 57 1–5. (doi:10.1369/jhc.2008.952770)