The conventions of writing are a bit different in the natural sciences.
Quotations are common in the humanities and social sciences, but fairly uncommon in the sciences.
This makes sense when you think about it, because papers in the natural sciences often cite hundreds of sources. As with every area of academic inquiry, there is no universally accepted format for formatting and documenting citations in scientific writing. Since the style is generally referred to as CBE style, we'll stick with that. CBE document formats Nuts and Bolts presents here a concise guide to CBE style. The book covers every major scientific discipline from astronomy to zoology.