A Strain-Promoted [3+2] Azide-Alkyne Cycloaddition for Covalent Modification of Biomolecules in Living Systems
2004 · paper · Chemistry
Reports that azides react with cyclooctyne derivatives under physiological conditions without a copper catalyst, driven by ring strain. The authors used a biotinylated cyclooctyne to modify living cells without apparent toxicity.
Checked: PDF from web.archive.org, fetched 5 Oct 2026. Page numbers are those of that PDF.
2 findings
Substance Reaction time for the Figure 3A dose-response experiment is given two ways: text "The cells were reacted with various concentrations of 5 for 1.5 h at room temperature" versus Figure 3 caption "(A) The cells were reacted with various concentrations of 5 for 1 h at room temperature".
- p. 2 Body text, paragraph beginning 'Finally, we investigated'
of 5 for 1.5 h at room temperature and then stained with FITC-
- p. 2 Figure 3 caption, panel (A)
The cells were reacted with various concentrations of 5 for 1 h at room temperature
- p. 2 Figure 3 caption, panel A
(A) The cells were reacted with various concentrations of 5 for 1 h at room temperature
- p. 2 main text, live cell labeling paragraph
various concentrations of 5 for 1.5 h at room temperature
Only the authors can say what is right here.
Judge's note: Read both passages on the page 2 image and crops. The text sentence is immediately followed by "As shown in Figure 3A", so it describes the same experiment as caption panel A (same cells, probe, room temperature, FITC-avidin, flow cytometry). Panel B is a time course and panel C is a separate 100 µM, 1 h experiment, so neither accounts for the 1.5 h. Nothing in the article reconciles the two values, and the Supporting Information is not among the files. Only the authors can say which duration is right.
Second check: another model agreed
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Reference or label Reference 14 pairs year and volume inconsistently: "J. Am. Chem. Soc. 1972, 95, 790-792." The paper's other J. Am. Chem. Soc. entries imply volume 95 is 1973 and 1972 is volume 94.
- p. 2 Reference 14
1972, 95, 790-792.
- p. 2 Reference 14
J. Am. Chem. Soc. 1972, 95, 790-792
- p. 2 Reference 14
1972, 95, 790-792
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: that J. Am. Chem. Soc. has published one volume per calendar year, so the year-to-volume offset is constant, and which of the year or the volume is the wrong one. On the page image, reference 14 reads "1972, 95, 790-792". The paper's own entries give 2004 = vol. 126 (footer), 2003 = vol. 125 (refs 2, 3a, 5b), 2002 = vol. 124 (ref 21) and 1992 = vol. 114 (ref 15), a constant offset of 1878. On that pattern 1972 would be volume 94 and volume 95 would be 1973. Whether the year or the volume is misprinted cannot be settled from the files.
Second check: another model agreed
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4 minor (typos and the like; most checked by the judge only)
Wording Text states "No detectable labeling of cells lacking azides was observed." but in Figure 3C the −Az bar for compound 5 is visibly above the −Az "No reagent" bar.
- p. 2 Body text, live-cell labeling paragraph
No detectable labeling of cells lacking azides was observed.
- p. 2 Figure 3C, −Az (black) bar for 5
5
Judge's note: On the Figure 3 image, panel C shows the black −Az bar for 5 at roughly 20 AU against roughly 7 AU for "No reagent" (my reading of a bar chart, with small error bars), so some azide-independent signal is visible there. The sentence directly follows the discussion of Figure 3A, where the −Az squares sit at baseline on a 0–800 AU scale, so the authors may mean panel A only. This is a wording ambiguity, not a clear error.
Second check: another model agreed
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Typo Author-name punctuation slips in the reference list: ref 14 "Jarrett, A. D,; Goebel, P." (comma for period); ref 12 "Wittig, G.; Krebs. A." (period for comma); ref 11 "Seo, T. S.; Ju J." (missing comma); likewise ref 15 "Kim J. S." and ref 16 "Shaw A."
- p. 2 Reference 14
Jarrett, A. D,; Goebel, P.
- p. 2 Reference 14
Jarrett, A. D,;
- p. 2 Reference 12
Krebs. A.
- p. 2 Reference 14
Jarrett, A. D,; Goebel
Judge's note: Checked on the page image and crops: all of these are printed as quoted and are not extraction artefacts. Every other entry uses the "Surname, I.;" pattern. Cosmetic, with evident fixes.
Second check: none (judge only)
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Typo Acknowledgment prints "GlyCAMIg, Tanya Leavy for model azides" without the hyphen; the protein is "GlyCAM-Ig" everywhere else in the text and in the Figure 2 caption.
- p. 2 Acknowledgment
GlyCAMIg, Tanya Leavy for model azides
- p. 2 Body text, first paragraph on the page
The recombinant glycoprotein GlyCAM-Ig
- p. 2 Acknowledgment
GlyCAMIg
Judge's note: On the crop, "GlyCAMIg" begins a line and is printed in full with no hyphen, so this is not a line-break artefact. The body text and Figure 2 caption consistently use "GlyCAM-Ig".
Second check: none (judge only)
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Typo The reprobing antibody is named two ways: text "The blot was stripped and reprobed with HRP-α-IgG" (also "α-IgG immunoreactivity" and "recognized by HRP-α-IgG") versus Figure 2 caption "reprobed with HRP-α-Ig" and blot label "α-Ig".
- p. 2 Body text, paragraph beginning 'As a point of comparison'
The blot was stripped and reprobed with HRP-α-IgG to confirm
- p. 2 Figure 2 caption
The blot was then stripped and reprobed with HRP-α-Ig
- p. 2 Figure 2 legend
reprobed with HRP-α-Ig
- p. 2 main text
reprobed with HRP-α-IgG
Judge's note: Confirmed on the page image: the text uses α-IgG three times, while the Figure 2 caption and the lower-panel label use α-Ig. The quotes were not found in the text layer only because α is extracted as "R". "α-Ig" may be deliberate shorthand, so this is a naming inconsistency and either form could be legitimate.
Second check: none (judge only)