Materials & methods: replicability not repetition

January 26, 2017

Dr. Kathryn Sobek, Filipodia Editor

 

The Materials and Methods section of a manuscript can be deceptive. It seems like it would be easy to just write out how the experiments were performed. However, almost every journal states in its author guidelines that the Materials and Methodssection should be concise but include sufficient detail so that the work can be replicated. I have compiled a list of tips that have helped me write the Materials and Methods section in order to meet the journal’s requirements.

 

 

  1. Provide adequate information about reagents used.It is expected that the company, city, state/province, and country be listed after any commercial reagent/kit and equipment used. It is also common to include the product or catalog number of the product used. This is especially useful if the company sells more than one type of that reagent (e.g. antibodies). The recipes for reagents should also be included. It is also important to include the sequences of primers used.
  2. Provide enough detail about the method so it can be replicated. Many times the protocol being used is from a previously published manuscript.  If this is the case, then cite the paper. However, confirm that the method is detailed in the paper you cite. I can recall many times that I have looked up a referenced paper only to find insufficient detail or another paper was referenced (thus sending me on a wild goose chase to find the original publication with the method). In addition, if any modifications have been made, then they need to be listed because readers need to know what you changed in order to replicate your results. Other details to include are controls used, number of replicates, and statistical methods.
  3. List the materials and methods in the same order as the results obtained from that method.However, the Materials and Methods section is not the place for results. Likewise, it is not necessary to detail the method again in the results section. I also recommend separating each method with a heading (e.g. Patient demographics, Flow cytometry, Statistical analysis, etc.).

 

You should always read your manuscript as if you were a peer-reviewer for your target journal — encountering the information for the first time. In this regard, Filipodia’s editors suggest that you ask the following important questions:

 

  1. Did I accurately and adequately describe the controls?
  2. Did I include all methods used for the data I am presenting in the Results section?
  3. Did I appropriately cite the other work on which I built my study’s methodology?
  4. Did I provide source information for each reagent listed?
  5. Did I include the dilutions, concentrations, and solution components unique to my experiment?
  6. Will someone outside of my research group be able to read the method described and replicate my experiment?

 

As always it is important to check the author guidelines for the journal you are submitting your manuscript to. Some journals have word limits or request that the majority of the methods be presented as Supplementary Material or even request that no materials are included in the Supplementary Material! I have also noticed that some journals have a website where you can upload detailed protocols that can be linked to the online version of your paper. Good luck!