The materials and methods section (or sometimes called the methods section) is the heart of your scientific article because it shows the credibility and validity of your work. The materials and methods section is a section in the scientific article containing the experimental design of the study. If there are major flaws in the research methodology, the reader will question the validity of the whole study.

After you submit your article to a peer-reviewed journal, the reviewers will judge the quality of your experimental design before accepting it.

Five common flaws that the reviewers find in a scientific article before rejecting are (Bordage, 2001):

  • Small and biased samples
  • Insufficient number of samples and incorrect research tools
  • Incorrect description and inappropriate use of statistics
  • Incorrect interpretation of the results
  • Writing that is unclear and hard to follow

The materials and methods section should include a clear and brief description of your research procedures. One important purpose of this section is to convince the readers that your work is valid. Another purpose is for researchers to use your methodology to guide his or her own experiments.

One thing to keep in mind when you write this section is to explain the procedures systematically and to include all necessary details.

A materials and methods section commonly has:

  • The experimental materials
  • The protocol
  • The methods used to measure the results
  • The methods used for data analysis
  • The equipment used in your experiments
  • The registration number of approval letter from an appropriate institution or ethics committee, if it is applicable.


The Common Elements of Materials and Methods

Materials

You should always check the journal guidelines for the format of materials and methods section before you start writing. For some journals, in the first subheading of materials and methods section you may describe experimental materials (for example molecules, cell lines, microorganisms, tissues, or plants) used in the research.

Below are some common examples of experimental materials:

  • Cell lines. Information about the sources, species, sex, and strains of the cell lines should be included.
  • Animals. The details about the source, species, strains, sex, weight, the number of animals used, and the type of animal model (for example db/db mouse) are necessary.
  • Chemicals. In addition to the chemical name, include amounts, volumes, concentration, the activity, the manufacturer, and its location.
  • Drugs. You need to include information such as generic name of the drugs, manufacturer, purity, concentration/doses, and route of administration.
  • Solutions. For the solutions, specify the solvent, pH, and temperature.
  • Culture media and buffers. The appropriate details for culture media and buffers are the components, the concentrations, temperature, volume, and pH.

Methods

The methods subheadings should have the details of your experimental design. Use subheadings to separate different procedures. Try to focus on how each procedure helped you answer your research questions before you start writing. Also, provide more details for each of the procedures in these subheadings. If possible, organize these subheadings based on the time sequence of your experiments.

How to write materials and methods for journal article

In one of these subheadings, you may explain your controls, length of the study, sample size, the treatments, the randomization of your samples, and the data collection procedure.

For each subheading, provide all the details about the data measurement and the details about the methods used.

For example, if you use quantitative real-time PCR, you should mention all treatments for your samples, RNA/DNA extraction, RNA/DNA quantification, primers (including their sequences), probe, reverse transcription kit, qPCR kit, the data, data normalization, PCR efficiency, and data analysis. Be sure to provide the type of the instrument, manufacturer, and model.

For the statistical analysis subheading, all details related to the statistical tests that you use are important. These details include preliminary analysis, study sample size, the type of data (mean, median, standard deviation, standards error, and confidence intervals), normalization of your data, statistical methods used, and information for the statistical software program (name of the program, company, city, state, and country).


Tips to write the materials and methods of scientific article

  • Write methods in past tense.
  • Ask other researchers (not involved in your study) to read it. After that, you can check if they understand the procedures.
  • Use a logical and chronological order to organize the methods section.
  • Describe statistical methods used for data analysis with all the necessary details and include the statistical significance level.
  • Organize the subheadings of the materials and methods in the same order as your result section.


References

6 Common Flaws To Look Out For in Peer Review . (2020, March 30). Publons. https://publons.com/blog/6-common-research-flaws-t...

Benos, D. J., Kirk, K. L., & Hall, J. E. (2003). How to review a paper. Advances in physiology education, 27(2), 47-52.

Bordage, G. (2001). Reasons reviewers reject and accept manuscripts: the strengths and weaknesses in medical education reports. Academic medicine, 76(9), 889-896.

Borja, A. (2005). 11 steps to structuring a science paper editors will take seriously. https://www. elsevier. com/connect/11-steps-to-structuring-a-science-paper-editors-will-take-seriously.

Faber, J. (2017). Writing scientific manuscripts: most common mistakes. Dental press journal of orthodontics, 22(5), 113-117.

Ghasemi, A., Bahadoran, Z., Zadeh-Vakili, A., Montazeri, S. A., & Hosseinpanah, F. (2019). The principles of biomedical scientific writing: Materials and methods. International journal of endocrinology and metabolism, 17(1).

Hoogenboom, B. J., & Manske, R. C. (2012). How to write a scientific article. International journal of sports physical therapy, 7(5), 512.

Shah, J. N. (2015). How to write ‘method’in scientific journal article. Journal of Patan Academy of Health Sciences, 2(2), 1-2.

Sharma, A. (2019). How to write an article: An introduction to basic scientific medical writing. Journal of minimal access surgery, 15(3), 242