Abstract: functions as an outline of the paper; include standard, searchable terms (keywords).
What is the problem domain (system under investigation)?
What is the specific research question?
What were the methods and results?
What are the conclusions?
Example: Nunez JK, Bai L, Harrington LB, Hinder TL, Doudna JA. 2016. CRISPR immunological memory requires a host factor for specificity. Molecular Cell 62: 824-833. Abstract: [Problem domain] Bacteria and archaea employ adaptive immunity against foreign genetic elements using CRISPR-Cas systems. To generate immunological memory, the Cas1-Cas2 protein complex captures 30-40 base pair segments of foreign DNA and catalyzes their integration into the host genome as unique spacer sequences. [Research question] Although spacers are inserted strictly at the A-T-rich leader end of CRISPR loci in vivo, the molecular mechanism of leader-specific spacer integration remains poorly understood. [Methods and results] Here we show that the E. coli integration host factor (IHF) protein is required for spacer acquisition in vivo and for integration into linear DNA in vitro. IHF binds to the leader sequence and induces a sharp DNA bend, allowing the Cas1-Cas2 integrase to catalyze the first integration reaction at the leader-repeat border. [Conclusions] Together, these results reveal that Cas1-Cas2-mediated spacer integration requires IHF-induced target DNA bending and explain the elusive role of CRISPR leader sequences during spacer acquisition.
Introduction: describes the general problem domain (system under investigation) and then focuses on the specific research question.
Methods and materials: provides enough detail to enable experiment to be reproduced by another researcher in your field. Standard experimental methods and apparatus do not need to be described at length.
Results: describes experimental outcomes, including figures and tables.
Discussion: explains meaning and significance of results (how do they advance the field?) and how they relate to the research question; describes limitations and further work suggested by study.
Acknowledgements: Unless there are separate sections for this information, name funding sources, declare any potential competing interests, and thank contributors who are not co-authors. For human- and animal-subject research, an ethics statement may be required identifying the review committee that approved the study and the relevant guidelines and regulations that governed the research.
References: A list of sources cited in your paper. Citations (both in-text and in the reference list) must be accurate and formatted in the journal's required style. Use a citation manager.
Supplementary information: supporting technical information (figures, protocols, methods, tables, additional data) too long or detailed to fit into the body of the paper.
You may want to write the sections of the paper in a different order than they will appear in the published work:
first focus on the results, discussion and methods (communicating the experimental procedures, outcomes and significance)
then work on the introduction, abstract and title (increasingly concise summaries of the work).
Use simple, concrete, active language ("We determined..." not "It was determined that...")
Start paragraphs with a topic sentence
Consider your audience: narrowly specialized or interdisciplinary?