PeptideStack
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220users

coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot traceability, and the single most common trap - reading area-per-cent purity as if it were content.

771 questions · sorted by votes · page 1 of 33

41 votes 5 answers42k views
How do I trace an SWB lot number back to a synthesis date?

This is my second independent submission on material from the same supplier. I can find plenty of assertions about this and almost no reasoning, which is usually a…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by mira_sundqvist 7.1k · 22 months ago
41 votes 4 answers39k views
Would you re-test a GLP-1 receptor agonist after sixteen weeks at 30 °C, or accept the original certificate?

What I have: a GLP-1 receptor agonist · sixteen weeks · 30 °C. I would rather over-plan the first cycle and simplify later. I am prepared to do the work if someone…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

908 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
asked by Dr_Priya_Raghunathan 49k · 2.3 years ago
41 votes0 answers38k views
How do I reconcile 99.4% from Janoshik with 97.1% from the supplier?

What I have: 99.4% · Janoshik · 97.1%. Before I write this off, I want to check whether it is a known failure mode. I have the lot number, the certificate and the…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
janoshik
janoshik

Janoshik Analytical, an independent third-party testing laboratory widely used by this community for HPLC purity, identity and quantified content…

139 questions
asked by colm_dunphy 8.2k · 23 months ago
41 votes 5 answers27k views
How many vials from a KP lot should I send for a quantified content assay?

Details up front: KP · a quantified content assay. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary;…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
cost-analysis
cost-analysis

Cost arithmetic done honestly: cost per milligram after dead-space loss, list versus net price, comparing a multi-dose vial to a fixed-dose pen,…

260 questions
content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

476 questions
asked by s_kalniete 57k · 22 months ago
41 votes0 answers26k views
How do I read a liraglutide chromatogram from PeptideMeter beyond the headline number?

The specifics, since they change the answer: liraglutide · PeptideMeter. I have the document in front of me and I can read the numbers. What I cannot do is interpret…

hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
liraglutide
liraglutide

A once-daily GLP-1 receptor agonist and the compound that established the class. Still relevant for its shorter half-life, its paediatric and…

235 questions
peptidemeter
peptidemeter

PeptideMeter, an independent peptide analytics and vendor-rating service. Use this tag for its published datasets, its rating methodology, and how…

107 questions
asked by swab_and_wait 13k · 2.2 years ago
40 votes5 answers66k views
What does a certificate with no method section imply?

The lot number on the vial matches the certificate, which at least rules out the easy problem. The figures are clear enough; the question is what they mean and what…

coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by harriet_lonsdale 35k · 2.4 years ago
40 votes 5 answers60k views
What does Medutest verification of Shanghai Sigma-Audley actually cover?

What I have: Medutest · Shanghai Sigma-Audley. I have read the primary source rather than the summary, which has left me with more questions. I understand the…

vendor-investigate
vendor-investigate

VendorInvestigate, an independent vendor review and verification service. Use this tag for questions about its verification criteria, what a…

113 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
medutest
medutest

Medutest, one of four independent testing and verification services referenced throughout this site. Use this tag for its methods, its report…

126 questions
asked by ravenna_pace 14k · 2.2 years ago
40 votes 5 answers40k views
Is a date of analysis from HJ sufficient basis to skip independent testing?

Setup, so nobody has to ask: date of analysis · HJ. I would like to define my thresholds before I have a result, for obvious reasons. I want a plan with explicit…

coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
harm-reduction
harm-reduction

Reducing avoidable risk where a decision has already been made: independent verification before use, sterility practice, dose arithmetic checked…

472 questions
asked by per_haugen 13k · 19 months ago
40 votes2 answers35k views
What does a 98.2% purity with a lot-specific certificate attached let me conclude?

Numbers first: 98.2% · lot-specific certificate. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear to…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
asked by birk_nordahl 16k · 19 months ago
40 votes3 answers35k views
What does 97.6% purity on a C18 column actually tell me about an ecnoglutide vial?

Stated plainly: 97.6% · a C18 column · ecnoglutide. I have read the primary source rather than the summary, which has left me with more questions. I understand the…

hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
ecnoglutide
ecnoglutide

A long-acting GLP-1 receptor agonist with a cAMP-biased signalling profile. A niche tag, mostly used for mechanism questions about biased agonism…

223 questions
asked by charge_state_3 16k · 21 months ago
40 votes5 answers34k views
What accept/reject threshold would you set for dulaglutide before seeing the result?

The method section is present, which is unusual enough that I want to make use of it. I would like to set this up properly once, rather than adjust it repeatedly. My…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
harm-reduction
harm-reduction

Reducing avoidable risk where a decision has already been made: independent verification before use, sterility practice, dose arithmetic checked…

472 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
dulaglutide
dulaglutide

A once-weekly GLP-1 receptor agonist built on an Fc fusion rather than fatty-acid acylation. Use this tag for questions about the fusion-protein…

200 questions
asked by olu_babatunde 6.2k · 2.1 years ago
40 votes5 answers29k views
How do I write up a PeptideMeter result on liraglutide so it is useful to others?

Setup, so nobody has to ask: PeptideMeter · liraglutide. I have done this once and I suspect I got away with it rather than got it right. For context: I keep records…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
harm-reduction
harm-reduction

Reducing avoidable risk where a decision has already been made: independent verification before use, sterility practice, dose arithmetic checked…

472 questions
peptidemeter
peptidemeter

PeptideMeter, an independent peptide analytics and vendor-rating service. Use this tag for its published datasets, its rating methodology, and how…

107 questions
liraglutide
liraglutide

A once-daily GLP-1 receptor agonist and the compound that established the class. Still relevant for its shorter half-life, its paediatric and…

235 questions
asked by ruaidhri_o_shea 25k · 2.1 years ago
40 votes 5 answers27k views
How do I reconcile 95.2% from Medutest with 99.4% from the supplier?

What I am working with: 95.2% · Medutest · 99.4%. This is not behaving the way I expected and I want to understand the discrepancy before I act on it. I have…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
medutest
medutest

Medutest, one of four independent testing and verification services referenced throughout this site. Use this tag for its methods, its report…

126 questions
asked by bridget_nyathi 12k · 22 months ago
40 votes 5 answers23k views
Would you re-test retatrutide after two weeks at minus 20 °C, or accept the original certificate?

What I am working with: retatrutide · two weeks · minus 20 °C. I am trying to build something sustainable rather than something thorough that I will abandon. I have…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

908 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
retatrutide
retatrutide

An investigational GLP-1, GIP and glucagon receptor tri-agonist, studied in the TRIUMPH programme. Not approved anywhere. Use this tag for…

251 questions
asked by lukas_sedlacek 16k · 2.1 years ago
40 votes5 answers21k views
Is a lot-specific certificate from SGN sufficient basis to skip independent testing?

For reference: lot-specific certificate · SGN. I am trying to build something sustainable rather than something thorough that I will abandon. I have already decided…

coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
harm-reduction
harm-reduction

Reducing avoidable risk where a decision has already been made: independent verification before use, sterility practice, dose arithmetic checked…

472 questions
asked by fresh_bac 9.7k · 23 months ago
39 votes 5 answers76k views
How does MKM compare to Chinese Peptide Company on documentation quality?

Conditions: MKM · Chinese Peptide Company. I am trying to choose between two options that are usually discussed as though only one exists. I am not optimising for…

vendor-comparison
vendor-comparison

Side-by-side comparison of suppliers on measurable axes - independently confirmed purity and content, lead time, cold-chain handling,…

388 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by bufferline42 30k · 2.1 years ago
39 votes 5 answers66k views
What accept/reject threshold would you set for liraglutide before seeing the result?

I have the report as a PDF with the chromatogram on page two, so I can quote specifics. I am at the decision point and I would rather think it through than improvise.…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
harm-reduction
harm-reduction

Reducing avoidable risk where a decision has already been made: independent verification before use, sterility practice, dose arithmetic checked…

472 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
liraglutide
liraglutide

A once-daily GLP-1 receptor agonist and the compound that established the class. Still relevant for its shorter half-life, its paediatric and…

235 questions
asked by sian_llewellyn 65k · 2.3 years ago
39 votes 5 answers61k views
How does KP compare to WuXi TIDES on documentation quality?

Concretely: KP · WuXi TIDES. I have used one of these for a while and I am considering switching, which requires a reason. What I care about is reproducibility,…

vendor-comparison
vendor-comparison

Side-by-side comparison of suppliers on measurable axes - independently confirmed purity and content, lead time, cold-chain handling,…

388 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by ben_akintola 10k · 2.0 years ago
39 votes 5 answers42k views
How does WWB compare to Shanghai ERP Biotechnology on documentation quality?

Conditions: WWB · Shanghai ERP Biotechnology. I have used one of these for a while and I am considering switching, which requires a reason. What I care about is…

vendor-comparison
vendor-comparison

Side-by-side comparison of suppliers on measurable axes - independently confirmed purity and content, lead time, cold-chain handling,…

388 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by pip_okonjo 13k · 20 months ago
39 votes5 answers41k views
How does JEEP compare to Qingdao Sigma Chemical on documentation quality?

The specifics, since they change the answer: JEEP · Qingdao Sigma Chemical. I want to know what the trade-off actually is rather than which option is fashionable. I…

vendor-comparison
vendor-comparison

Side-by-side comparison of suppliers on measurable axes - independently confirmed purity and content, lead time, cold-chain handling,…

388 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by orla_sheridan 18k · 2.1 years ago
39 votes 5 answers41k views
Does MKM issue lot-specific documentation, or a batch certificate?

This is my second independent submission on material from the same supplier. I have the document in front of me and I can read the numbers. What I cannot do is…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by coring_risk 27k · 22 months ago
39 votes5 answers37k views
How many vials from a GL Biochem lot should I send for a residual-solvent screen?

Setup, so nobody has to ask: GL Biochem · a residual-solvent screen. I would rather understand the derivation than memorise the outcome. Two people I asked gave two…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
cost-analysis
cost-analysis

Cost arithmetic done honestly: cost per milligram after dead-space loss, list versus net price, comparing a multi-dose vial to a fixed-dose pen,…

260 questions
residual-solvent
residual-solvent

Solvents left behind by synthesis and purification - acetonitrile, TFA, DMF, DCM - their ICH limits, how they are measured by headspace GC, and…

14 questions
asked by meniscus_film 32k · 18 months ago
39 votes5 answers37k views
What would you ask Shanghai ERP Biotechnology before a first order that they cannot fake?

I am comparing three suppliers on documentation rather than on price. I have done this once and I suspect I got away with it rather than got it right. For context: I…

vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
asked by coldpack_88 50k · 19 months ago
39 votes 5 answers31k views
Is a chromatogram from GGPeps sufficient basis to skip independent testing?

The particulars: chromatogram · GGPeps. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in view and I would like the…

coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
harm-reduction
harm-reduction

Reducing avoidable risk where a decision has already been made: independent verification before use, sterility practice, dose arithmetic checked…

472 questions
asked by coring_risk 27k · 19 months ago
Sponsored

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HPLC purity, identity confirmation and quantified content on the vial you actually hold. Reports arrive with the chromatogram attached, not just a number.

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