Materials and methods (“How?”)

There are different traditions between different branches of the natural sciences for the allocation of content between Materials and methods (also called Experimental part in many chemistry journals) and Results. There are also different traditions on where the Materials and Methods section should be placed – after the introduction or after the discussion. Ask your supervisor what applies to your paper.

For experimental work in for example clinical toxicology and physiology, the experiments should be described in the Materials and methods section. On the other hand, in the more laboratory branches of biology and chemistry, Materials and methods should only contain specific materials and methods, while the experiments in which you have used the materials and methods are described in the Results section. Also divide that section into subdivisions with sub-headings. That part should be detailed.

In Materials and methods you should also describe how you processed your data and what statistical analyses you have used. You do not need to describe methods that are described in all statistical books (for example t-tests), but you have to describe more unusual methods. Always specify the computer programs or databases that you have used in the calculations. Ethical approvals should be mentioned for experiments on humans and animals. Usually you do not need ethical approval for only interviews.

Begin by describing experimental populations, biological materials, chemical substances or drugs used. This can be patients, healthy volunteers, bacteria, laboratory animals, viruses, tissue cultures, etc. Then describe how they were treated or cultivated, or chemical reagents and solvents and their chemical quality (% purity). Use tables for this.

The method descriptions should include recipes for all solutions and media, volumes, times, temperatures etc. in an easily accessible form. If you refer to other works for detailed descriptions of methods, previous experimental results or the like, you must provide a brief summary in your text, so that the reader does not need to go to the library to understand your text. Do not write "Cation concentrations were determined according to NN". Instead write "The amount of substitutable cation was determined after extraction with ammonium acetate, in accordance with NN".

It is not enough to write that you have studied the literature. You should specify which databases you used, what search terms you used, and what the search results looked like. Use tables for this.

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