You may want to identify certain types of equipment by vendor name and brand or category (., ultracentrifuge vs. prep centrifuge), particularly if they are not commonly found in most labs. It is appropriate to report, parenthetically, the source (vendor) and catalog number for reagents used, ., " ....poly-L-lysine (Sigma #1309) ." When using a method described in another published source, you can save time and words by providing the relevant citation to the source. Always make sure to describe any modifications you have made of a standard or published method.
For an excellent source on English composition, check out this classic book by William Strunk, Jr. on the Elements of Style. Contents include: Elementary Rules of Usage, Elementary Principles of Composition, Words & Expressions Commonly Misused, An Approach to Style with a List of Reminders: Place yourself in the background, Revise and rewrite, Avoid fancy words, Be clear, Do not inject opinion, Do not take shortcuts at the cost of clarity, … and much more. Details of The Elements of Style by William Strunk, Jr. partially available online at . Note: William Strunk, Jr. (1869–1946). The Elements of Style was first published in 1918.