I'm about to write my thesis (which will also be the basis of a journal article, though not written by me). I was wondering how the materials & methods section should be written, when an experiment has multiple phases. I personally find it clearer, when for each sub-experiment, the materials are listed separately. There will be some repetitions of general materials (i.e. pipets, containers, etc.), however. I was just wondering what can be considered the best way to do this. Another thing - during my studies, lab assistants sometimes insisted the materials section should list exactly how much of a certain material is used (i.e. 10µl solution). Is this necessary, when the exact amount is already mentioned in the methods section?
Unless you are specifically precluded by the regulations of your institution, in your thesis there is typically great latitude to present material in whatever form you find clearest.
As such, if you think that it is clearer to separate each method into its own sub-section, you should do so. Likewise, if you have separated materials and methods cookbook-style and you think it is clearer to say a measurement one rather than twice, then let clarity of presentation be your guide. If your readers or your institutional regulations disagree with you, however, then you will likely need to change to a form that they prefer.
You usually have a lot of latitude. I'd do the following:
- Introduction. Overview of the work, overview of the following chapters.
- State of the art. Critical review of the relevant literature.
- Overview of the experiment, phases, objectives of each, how they fit together.
Phase 1 of the experiment.
4.1. Discussion of method.
Phase 2 of the experiment
5.1. Discussion of method
and so on. Keep each phase as a coherent whole, Think of your gentle reader, who might just be interested in details of phase 3, and couldn't care less for the rest (they want to adapt it to a different setting, whatever).