Before & After
examples that help you write
We demonstrate how to use specific writing techniques to:
- organize information, and
- drive the narrative.
We select excerpts of often-cited articles that are significant and accessible, but written in poor academic English.
We hope our B&A examples are helpful to your writing.
Patrick Han & the [ sayedit.com ] team
BEFORE
Original: Sanger et al. PNAS 74, 1977, 5463-67
> 60,000 citations
A new method for determining nucleotide sequences in DNA is described. It is similar to the “plus and minus” method [Sanger, F. & Coulson, A. R. (1975) J. Mol. Biol. 94, 441-448] but makes use of the 2′,3′-dideoxy and arabinonucleoside analogues of the normal deoxynucleoside triphosphates, which act as specific chain-terminating inhibitors of DNA polymerase. The technique has been applied to the DNA of bacteriophage ϕX174 and is more rapid and more accurate than either the plus or the minus method.
AFTER
Editing Technique:
Rewrite in the Active Voice
We present a new DNA nucleotide sequencing method with greater speed and accuracy than the current “plus and minus” method [Sanger, F. & Coulson, A. R. (1975) J. Mol. Biol. 94, 441-448]. Our method uses 2′,3′-dideoxy and arabinonucleoside analogues of the normal deoxynucleoside triphosphates as specific chain-terminating inhibitors of DNA polymerase. We demonstrate this method by sequencing the DNA of bacteriophage ϕX174.
BEFORE
Original: Saiki et al. Science 239, 1988, 487-91
> 20,000 citations
A thermostable DNA polymerase was used in an in vitro DNA amplification procedure, the polymerase chain reaction. The enzyme, isolated from Thermus aquaticus, greatly simplifies the procedure and, by enabling the amplification reaction to be performed at higher temperatures, significantly improves the specificity, yield, sensitivity, and length of products that can be amplified. Single-copy genomic sequences were amplified by a factor of more than 10 million with very high specificity, and DNA segments up to 2000 base pairs were readily amplified. In addition, the method was used to amplify and detect a target DNA molecule present only once in a sample of 105 cells.
AFTER
Editing Technique:
Present Narrative Tense
We use a thermostable polymerase enzyme to improve the known polymerase chain reaction in vitro DNA amplification. The new enzyme enables higher temperature amplification, which simplifies the overall procedure and enhances the specificity, yield, sensitivity and length of the target product. Our new method can amplify single-copy genomic sequences of up to 2000 base pairs by a factor of more than 10 million with very high specificity. We demonstrate this by detecting the presence of a single target DNA molecule in a sample of 105 cells.
BEFORE
Original: Chomczynski et al. Anal. Biochem. 162, 1987, 156-9
> 60.000 citations
Guanidinium thiocyanate and chloride are among the most effective protein denaturants (1,2). As a strong inhibitor of ribonucleases, guanidinium chloride was first introduced as a deproteinization agent for isolation of RNA by Cox (3). Since then guanidinium extraction has become the method of choice for RNA purification, replacing phenol extraction. Guanidinium methods have been used successfully by Chirgwin et al. (4) to isolate undegraded RNA from ribonuclease-rich tissues like pancreas. Chirgwin’s protocol for ultracentrifugation of a guanidinium thiocyanate lysate through CsCl cushion has become one of the most frequently used isolation of undegraded RNA. In the present report, a new rapid procedure combining guanidinium thiocyanate and phenol-chloroform extraction is described…
(see entire B&A)
AFTER
Editing Technique:
Break up a Single Paragraph into Two
Current RNA extraction methods that use guanidinium thiocyanate and chloride as deproteinization agents are outcompeting older methods such as phenol extraction (1-3). Recent breakthroughs have used the ultracentrifugation of a guanidinium thiocyanate lysate through CsCl cushion to extract undegraded RNA from ribonuclease-rich tissues, expanding the capabilities of guanidinium methods (4). However, the need for a ultracentrifugation step still hinders simultaneous processing of samples in large number, greatly reducing the RNA yield.
Here, we describe a new procedure that combines guanidinium and phenol extraction methods…
(see entire B&A)
BEFORE
Original: Thompson et al. Nucleic Acid Res. 25, 1997, 4876-82
> 30,000 citations
AFTER
Editing Technique:
Removal of Unnecessary Adverbs
BEFORE
Original: Baron & Kenny J. Pers. Soc. Psychol. 51, 1986,
1173-82, > 45,000 citations
AFTER
Editing Technique:
Using action verbs instead of “to be”