Studies on the Chemical Nature of the Substance Inducing Transformation of Pneumococcal Types
Journal of Experimental Medicine, 1944 · paper · Biomedicine
The supplied text is a 1979 anniversary introduction to the 1944 paper on pneumococcal transformation, not the paper itself. It recounts that the work identified DNA as the transforming factor and redirected biology toward DNA.
Checked: PDF from europepmc.org, fetched 4 Oct 2026. Page numbers are those of that PDF.
2 findings
Substance "the reaction system containing the 0.003 µg. has a volume of 2.25 cc., this represents a final concentration of the purified substance of 1 part in 600,000,000": 0.003 µg in 2.25 cc is about 1 part in 750,000,000.
- p. 21 Quantitative Determination of Biological Activity, last paragraph
this represents a final concentration of the purified substance of 1 part in 600,000,000
- p. 21 Table IV footnote
0.2 cc. of each dilution added to quadruplicate tubes containing 2.0 cc. of standard serum broth. 0.05 cc.
- p. 21 last paragraph, Quantitative Determination of Biological Activity
this represents a final concentration of the purified substance of 1 part in 600,000,000.
- p. 21 Quantitative Determination of Biological Activity, last sentence
a final concentration of the purified substance of 1 part in 600,000,000
Only the authors can say what is right here.
Judge's note: Checked on the p.21 image. The stated volume of 2.25 cc matches the protocol (0.2 + 2.0 + 0.05 cc). Using the exact 10^-4.5 amount (about 0.00316 µg) gives about 1 in 710 million, which still does not reach 600 million. Only the authors can say whether the amount, the volume or the ratio is intended.
Second check: another model agreed
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Reference or label Reprint note: "pages 137-158 are counted as blind folios 303 through 325". The 22 pages run 303-324; folio 325 (and 326) belongs to the unpaginated Plate 1.
- p. 6 Reprint note
pages 137-158 are counted as blind folios 303 through 325
Judge's note: Checked on the p.6 image. The note itself is folio 302, so original p.137 is PDF p.7 = folio 303 and p.158 is PDF p.28 = folio 324. PDF p.29 (Plate 1) is folio 325. This matches the stated inclusive range 297-326 ending 'through Plate 1'. The range given for 137-158 is therefore one folio too long.
Second check: another model agreed
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10 minor (typos and the like; most checked by the judge only)
Reference or label Ref. 27 gives the title as "Genetics and the origin of the species".
- p. 27 Bibliography, ref. 27
Genetics and the origin of the species
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: Dobzhansky's Columbia University Press book is titled 'Genetics and the Origin of Species', without 'the' before 'species'. The p.27 crop confirms the printed wording. The book's actual title cannot be checked from the files.
Second check: another model agreed
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Wording "Four purified preparations were analyzed for content of nitrogen, phosphorus, carbon, and hydrogen", yet Table I gives carbon and hydrogen only for preparations 37 and 42 (dashes for 38B and 44).
- p. 15 Elementary Chemical Analysis paragraph
Four purified preparations were analyzed for content of nitrogen, phosphorus, carbon, and hydrogen.
- p. 15 Table I, rows 38B and 44
—
Judge's note: Checked Table I on the p.15 image. All four preparations have N and P values, but only two have C and H. The sentence is imprecise rather than wrong in substance.
Second check: another model agreed
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Wording Table I N/P ratios: preparation 42 '15.36 9.04 1.69' and preparation 44 '13.40 8.45 1.58' do not round from the printed N and P (1.70 and 1.59).
- p. 15 Table I, preparation 42
15.36
- p. 15 Table I, preparation 42 N/P ratio
1.69
- p. 15 Table I
15.36 9.04 1.69
- p. 15 Table I
13.40 8.45 1.58
Only the authors can say what is right here.
Judge's note: Checked the p.15 image. Preparations 37 and 38B and the theory row round correctly. Rows 42 and 44 come out 0.01 low. Truncation would explain those two rows but would make row 37 read 1.65. The ratios may have been computed from unrounded analyses, so only the authors can say. The discrepancy is minor.
Second check: another model agreed
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Wording Summary point 3 credits the analyses with showing "no demonstrable protein, unbound lipid", while the Results state "no specific tests for the presence of lipid in the purified material have been made".
- p. 26 Summary, point 3
the active fraction contains no demonstrable protein, unbound lipid,
- p. 15 Qualitative Chemical Tests
Although no specific tests for the presence of lipid in the purified material have been made
Judge's note: Compared the p.26 Summary with the p.15 Qualitative Chemical Tests. The only lipid evidence is indirect: activity survives alcohol/ether extraction of crude material and chloroform treatment. The Summary's hedge 'within the limits of the methods' softens the claim, but the wording still goes beyond what is reported.
Second check: another model agreed
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Wording Text says "a commercial preparation of pancreatin were also tested ... The results are summarized in Table II", but Table II has no pancreatin row, and p.149 later cites pancreatin as containing the inactivating enzyme.
- p. 16 Text below Table II
Pneumococcal autolysates and a commer- cial preparation of pancreatin were also tested.
- p. 16 Text
The results are summarized in Table II
- p. 16 Table II rows
Normal dog and rabbit serum
- p. 19 Fluoride inhibition paragraph
dog intestinal mucosa, pan- creatin, or normal sera
Only the authors can say what is right here.
Judge's note: The p.16 image shows Table II with only five rows: dog intestinal mucosa, rabbit bone phosphatase, swine kidney, pneumococcus autolysates, and normal dog and rabbit serum. No pancreatin result is reported anywhere I checked. The p.19 fluoride paragraph names pancreatin as a source of the enzyme.
Second check: another model agreed
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Typo Lederberg foreword reads "a position I shared though the forties"; 'through' is meant.
- p. 4 Lederberg introduction, paragraph 3
a position I shared though the forties
Judge's note: The crop of p.4 shows 'though the forties' in print. The sentence is ungrammatical as printed, so this is a typo.
Second check: none (judge only)
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Typo "with the exception of desoxycholate ex- / extraction and enzyme treatment": the syllable 'ex-' is duplicated across the line break.
- p. 14 Effect of Temperature paragraph
with the exception of desoxycholate ex- extraction and enzyme treatment
Judge's note: The p.14 crop shows 'ex-' at the end of one line and the full word 'extraction' at the start of the next.
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Typo "completely destoyed the rabbit serum depolymerase" should read 'destroyed'.
- p. 19 First paragraph
completely destoyed the rabbit serum depolymerase
Judge's note: The p.19 image shows 'destoyed' in the first paragraph.
Second check: none (judge only)
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Typo "analytical ultra- centrigue" should read 'ultracentrifuge'.
- p. 20 Physicochemical Studies paragraph
analytical ultra- centrigue
Judge's note: The p.20 crop shows 'centrigue' at the start of the line in the Physicochemical Studies paragraph.
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Typo Conclusion: "a nucleic acid of thedesoxy-ribose type" is missing the space between 'the' and 'desoxy-'.
- p. 26 CONCLUSION
a nucleic acid of thedesoxy-
Judge's note: In the Conclusion paragraph of the p.26 image, 'the' and 'desoxy-' run together with no word space.
Second check: none (judge only)