Write the entirety of your research paper before you start your abstract. Consider the four parts that make up your abstract, described by Columbia University as the purpose, methods, results and conclusion, as you write the main body of your article.
Write your first draft, which should be a 300 to 400 word single paragraph summarizing everything you think is relevant to your biological study. Construct your abstract with short, concise sentences, but remember this is a first draft so don't omit anything. You must describe each element of your biological study. Your abstract needs to be less technical than the rest of your paper, according to Columbia University, and entice viewers to read the entirety of your paper.
Edit your abstract so it is between 100 and 250 words. Ensure your abstract is only one paragraph, and addresses the four key areas required of an abstract. Cut out any unnecessary words from your first draft to reduce it to the required word count. Read your abstract either in your head or aloud to verify it still reads well and makes sense after your intensive editing.
Invite a tutor or a fellow student to read over your abstract. Ask her to describe your study to you after reading your abstract and check for any missing details you may have omitted from it. Add any additional details where they are missing and have another student or tutor repeat the reading and describing process. Finalize your abstract once your tutor or classmate is able to wholly and succinctly describe your abstract.