DNA extraction was performed in the laboratory today. Leaves from the plant Brachypodium distachyon were frozen in liquid nitrogen and placed inside a 2-mL round-bottom tube with two metal balls. A machine was used to shake the tubes vigorously, allowing the balls to grind up the frozen leaves inside into a fine powder. Detergent was added to the powder to break down the cell and nuclear membranes, and ethylenediaminetetraacetic acid was added to stop the cells’ enzymes from degrading the DNA. The tube was then incubated and chilled in ice. A potassium solution was then added to the tube, which caused the proteins and carbohydrates to precipitate. The tube was centrifuged, causing the precipitated contents to form a solid pellet. The supernatant containing the DNA was transferred to a new, clean 2-mL tube, and isopropanol was added to the solution, which caused the DNA to precipitate. The tube was centrifuged, causing the precipitated DNA to form a small, clear pellet at the bottom of the tube. The supernatant was extracted, and the DNA pellet was washed with 70% ethanol. Lastly, the DNA pellet was dissolved in a preservation solution.
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Suggestions
This paragraph is very hard to understand mainly because it has big words next time maybe you can give a little background information to help the reader understands better.
Suggestions.
"A machine was used to shake..." was it a centrifuge? If so, I would say so because your audience likely knows what that is. With the use of that word, you could shorten the sentence because you would be cutting out some unneccesary description.
"ethylenediaminetetraacetic acid" is there a shortened version of this name, like LDA is for lithium di-isopropyl amide? Maybe you could put that in parentheses next to the acid.
This is a summary of what was done in lab for a day I am assuming, but with these minor changes, I feel you could easily use this in your report. It is very well written.
Suggestions
In class the other day we were advised to avoid passive voice and rather use active voice. Every time a sentence includes "was" it's passive voice. For example, "DNA extraction was performed in the laboratory today" is passive voice.