MLA Quotation Punctuation

The punctuation for integrating academic quotes is a little different than dialogue punctuation. When a quotation ends a sentence and the parenthetical citation is at the end, the period should come after the citation. Additionally, there are separate rules for long quotations.

Quotes That End a Sentence

When a quote with citation ends a sentence, the period should go after the citation because the citation belongs to that sentence.

  • Example: In “Synthetic Biology–Putting Engineering into Biology,” Heinemann and Panke theorize about the future of synthetic biology, declaring, “Now, synthetic biology is adopting a very ambitious agenda in building novel biological entities” (2797).

Note the order of the punctuation: Quotation mark, citation, and then period.

Use of Ellipses

If only part of a quote is needed, it is possible to omit information and replace it with ellipses. Ellipses (. . .) are used when information is omitted from the middle of a quote.

  • Example: Heinemann and Panke theorize about the importance of engineering in the context of biological fabrication when they assert, “Synthetic biology investigates . . . the process of engineering biological systems” (2790).

Using Brackets

Sometimes information is missing or inaccurate in a quote. Words can be added or changed to a quote by using brackets. Changes can be used to correct tense or to add necessary information. Brackets can also be used to make the pronouns in a quote consistent. However, brackets should not be used to change the meaning of the quote.

Brackets for Pronoun Consistency

  • Nathan said, “I want people to understand me.”
  • Nathan said that he wants people “to understand [him].”
  • In this example, the pronoun is changed so it is consistent with the rest of the sentence.

Brackets for Additional Information

  • Nathan said, “I need the people to arrive on that day.”
  • Nathan said, “I need the people to arrive on [Sunday October 29th ].”
  • Information can be added to a sentence with brackets for clarity or understanding.

Quote Introduced with a Colon

If the introduction to a quote is a full sentence, then a colon can be used. Choosing a colon instead of a comma creates a longer pause and puts more emphasis on the quote.

  • When alone in a room, Descartes had a thought: “I think, therefore I am” (Descartes).

Block Quotes

When using a long quote (longer than four typed lines) block quotes should be used. Block the quote by one-half inch from the left margin. If the paper is double spaced, then the block quote should be double spaced. There are no quotation marks needed for block quotes, and the citation follows the quote, outside of the period.

  • Heinemann and Panke highlight the importance of DNA synthesis and protein engineering in relation to synthetic biology in the following statement:
    • Synthetic biology is interpreted as the engineering-driven building of increasingly complex biological entities for novel applications. Encouraged by progress in the design of artificial gene networks, de novo DNA synthesis and protein engineering, we review the case for this emerging discipline. (2790)


Heinemann, M., & Panke, S. (2006). Synthetic biology-putting engineering into biology. Bioinformatics, 22(22), 2790-2799. doi:10.1093/bioinformatics/btl469

Russell, T., Brizee, A., Elizabeth, A. Keck, R., Paiz, M., Campbell, M., Fuentes, Owl Purdue Staff. (2012). MLA Formatting Quotations. Retrieved October 26, 2017, from

UNC College of Arts and Science. (n.d.). Quotations. Retrieved October 29, 2017, from

Contributor: Nathan Lachner