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Chemistry & Biochemistry: ACS Style Guide

Research guide for chemistry

American Chemical Society (ACS)

ACS - In text

ACS Style - In texting:

There are three formats, but the same format needs to be maintained throughout the paper:

Format 1 uses superscript numbers e.g.,

Bacillus subtilis is a Gram-positive bacterium1 and ...


Format 2 uses italic numbers in parentheses e.g.,

Bacillus subtilis is a Gram-positive bacterium (1) and ...


Format 3 uses author-date references with the year of publication in parenthesis e.g.,

Bacillus subtilis is a Gram-positive bacterium (Jones, 2019) and ...

For your biology 202 papers, use format 1 (i.e., superscript numbers):

One or two Authors:

Jones18 has argued that …

When citing two authors, both last names need to be joined by the word, and,


The synthesis described by Jones and Smith13 

MORE than TWO Authors:

When citing more than two authors, use the first author listed followed by et al.


Miller et al.54 have found the first ...​

Multiple References:

When citing more than one reference at the same point within the text, list the references in order separating by a comma without spaces between each reference.  If the references are part of a consecutive series, then use a dash for a range of THREE of more references without spaces.

e.g., stated in the literature,4,8,15 

...were reported.1,5-7

When the citation includes more than one reference by the same principle author and other coauthors, use the principle author's name followed by co-workers and / or colleagues,


Becker and co-workers4,5,8 have discovered that …

ACS - author-date citation style

With ACS - author-date citation style, the references need to be:

  • in alphabetical order by author's last name
  • multiple references by the same author should be listed in chronological order. For two or more references by the same author(s) AND same publication year, consecutive lowercase letters need to be added to the years (like with the in-text citing within the body of the paper)

Why Cite?

ACS - References

The reference list should come at the end of your paper and needs to provide enough information so that the reader can identify and locate the document that is cited in-text. With ACS style, include all author names in a reference citation. Head the reference list as REFERENCES.

Papers using a numerical citation style system list the references in numerical order,

(1) ...
(2) ...
(3) ...

LOOK at one of the ACS journals to see how the reference list appears with examples like in the Journal of Medicinal Chemistry.

Reference Examples

(1) Tobisch, S.; Zuhlke, D.; Bernhardt, J.; Stulke, J.; Hecker, M. Role of CcpA in regulation of the central pathways of carbon catabolism in Bacillus subtilisJ. Bacteriol. 1999181, 6996−7004.

(2) Furlan, R. L. E.; Cousins, G. R. L.; Sanders, J. K. M. Molecular amplification in a dynamic combinatorial library using noncovalent interactions. Chem. Commun. 2000, 1761−1762.

(3) Bridges, A. Chemical inhibitors of protein kinases. Chem. Rev. 2001101, 2541−2571.

(4) Clarke, S. E., Jones, B. C. Human cytochrome P450s and their role in metabolism-based drug-drug interactions. In Drug-Drug Interactions, 2nd ed.; Rodrigues, A. D., Ed.; Marcel Dekker: New York, 2002; Vol. 179, pp 55−88. 

(5) Cully, D.; Singh, S. B. Platensimycin is a selective FabF inhibitor with potent antibiotic properties. Nature 2006441, 358−361. 

(6) U. S. Environmental Protection Agency. (accessed Nov 7, 2019).

(7) National Library of Medicine. Environmental Health & Toxicology. (accessed May 18, 2023).


When citing an image or figure in your paper, scholars generally incorporate the citation for the full source it came from - instead of simply citing it as an image. Note to capitalize the word Figure when it is followed by the figure number and superscript to the reference.



As Bridges shows in Figure 1¹, the mechanism of action depends on . . .


(1) Bridges, A. Chemical inhibitors of protein kinases. Chem. Rev. 2001101, 2541−2571.