We describe an application of controlled text authoring to biological experiment reports. This work is the result of a collaboration between a computational linguistics team and biological experts from a startup company specializing in protein production studies. We start by presenting our semantically-controlled authoring system, MDA (Multilingual Document Authoring), an expressive model for specifying well-formedness conditions both at the level of the document content and at the level of its textual realization. We then discuss the practical needs of experiment documentation in bioengineering. We then go on to describe the prototype we have developed for this application domain, along with a preliminary evaluation. Finally we discuss a promising new idea emerging from the experimentation but which seems of wider applicability: how the authoring system represents a step towards integrating the formalization of an experimental protocol with its associated textual documentation.