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ForumsCOA & Analytical TestingUnderstanding peptide purity percentages — what worked for you? Page 7

Understanding peptide purity percentages — what worked for you?

LondonLisa Wed, Apr 16, 2025 at 10:14 AM 38 replies 2,088 viewsPage 7 of 8
PeptideSynthNJ
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Princeton, NJ
May 22, 2025 at 7:45 AM#31

One concrete data point for the thread. If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way. Most of the apparent contradictions in these threads dissolve at that step.

44 17wanda_boise, NurseAsh_DET, BenResearch_OR and 41 others
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Dr.ReproEndo
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Scottsdale, AZ
May 24, 2025 at 8:02 PM#32

One thing that is still open after SleepDoc_PDX’s answer:

Was that from a primary source or from a summary of one?

45 18andrew_nyc, Dr.EndoEP, GraceAZ_72 and 42 others
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Dr.LipidDallas
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May 27, 2025 at 8:18 AM#33
PeptideSynthNJ said:
If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way.

Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. Filing an objection on the n=1 problem. Personal experience is genuine evidence about one person and very weak evidence about anybody else, and this thread keeps promoting the first into the second.

46 19cory_ATX, lori_vegas, Dr.PulmRoch and 43 others
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matt_MKE
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Sep 2024
Milwaukee, WI
May 29, 2025 at 8:32 PM#34
PeptideSynthNJ said:
If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way.

That is correct as far as it goes, and here is where it stops going. Yes, and the corollary is less popular: if the reasoning holds, it also holds where it produces an answer we do not like.

47 20carl_compliance, DanielChem_CHI, marco_milano and 44 others
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kim_atl_prep
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Atlanta, GA
Jun 1, 2025 at 8:45 AM#35
PeptideSynthNJ said:
If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way.

Genuinely useful, thank you. I had the facts and not the framework. Adding it to my notes with a link back to this thread.

48 21PedsEndoPhilly, SleepDoc_PDX, RegAffairsDC and 45 others
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