peptidemeter

PeptideMeter, an independent peptide analytics and vendor-rating service. Use this tag for its published datasets, its rating methodology, and how to reconcile a PeptideMeter figure with a laboratory certificate.

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14 questions · sorted by votes

35 votes5 answers58k views

Why does hydrolysis accelerate at minus 20 °C rather than proceeding linearly?

Details up front: hydrolysis · minus 20 °C. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would like to know how…

peptide-stability

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

832 questionsstorage

storage

Storage conditions and their evidence base: minus twenty degrees for powder, refrigerated for solution, protection from light, and what the…

646 questionshplc

hplc

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

466 questionspeptidemeter

peptidemeter

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

14 questionsasked by g_paskevicius 44k · 22 months ago

31 votes0 answers7.7k views

What would you ask Xi’an Mokemei Biotechnology before a first order that they cannot fake?

The lane and the lead time matter as much as the material for what I am doing. I want a method I can write down and repeat, not a rule of thumb. I would rather…

vendor-vetting

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

436 questionscoa

coa

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

749 questionsbatch-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…

865 questionspeptidemeter

peptidemeter

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

14 questionsasked by t_oyelaran 41k · 11 months ago

24 votes 5 answers16k views

Is a 97.1% result from VendorInvestigate comparable to 96.4% from Janoshik?

Conditions: 97.1% · VendorInvestigate · 96.4% · Janoshik. These are treated as interchangeable and I do not think they are. If both are acceptable I would like to…

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…

788 questionsbatch-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…

865 questionsreference-standard

reference-standard

Certified reference materials and in-house standards: traceability, the certificate of the standard itself, system suitability, and why every…

179 questionspeptidemeter

peptidemeter

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

14 questionsasked by mz_4113 99k · 12 months ago

23 votes 5 answers34k views

How does MKM compare to Qingdao Saber Technology on documentation quality?

For reference: MKM · Qingdao Saber Technology. The comparison I want does not seem to exist anywhere in a form I can evaluate. I have read the arguments for each and…

vendor-comparison

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

351 questionscoa

coa

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

749 questionsvendor-vetting

vendor-vetting

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

436 questionspeptidemeter

peptidemeter

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

14 questionsasked by zeynep_arslan 20k · 14 months ago

18 votes3 answers4.4k views

What system suitability numbers should I insist on seeing before I believe a purity or content figure?

I have started asking labs for "the system suitability data" and getting back either silence, a shrug, or a screenshot of six retention times. I clearly do not know…

reference-standard

Certified reference materials and in-house standards: traceability, the certificate of the standard itself, system suitability, and why every…

179 questionshplc

hplc

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

466 questionscoa

coa

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

749 questionsbatch-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…

865 questionspeptidemeter

peptidemeter

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

14 questionsasked by tenth_of_a_unit 40k · 4 months ago

12 votes 5 answers19k views

Is a batch certificate from ERP sufficient basis to skip independent testing?

What I have: batch certificate · ERP. I would rather over-plan the first cycle and simplify later. I am prepared to do the work if someone can tell me which work…

coa

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

749 questionsbatch-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…

865 questionsharm-reduction

harm-reduction

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

445 questionspeptidemeter

peptidemeter

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

14 questionsasked by k_szabo 45k · 14 months ago

12 votes0 answers3.4k views

Has anyone independently verified an MKM semaglutide batch COA?

For reference: MKM · semaglutide. Somebody stated this to me confidently and I would like to check it before repeating it. I would accept a well-reasoned negative…

vendor-vetting

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

436 questionscoa

coa

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

749 questionsbatch-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…

865 questionspeptidemeter

peptidemeter

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

14 questionsasked by ten_mg_vial 16k · 13 months ago

11 votes5 answers14k views

What does a purity figure on an SWB report change about how I read it?

Stated plainly: purity figure · SWB. I would like help reading this properly rather than being told what conclusion to reach. I have the full report including the…

coa

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

749 questionsbatch-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…

865 questionsvendor-vetting

vendor-vetting

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

436 questionspeptidemeter

peptidemeter

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

14 questionsasked by plunger_stop 18k · 2.1 years ago

11 votes5 answers12k views

Would you re-test dulaglutide after eight weeks at 37 °C, or accept the original certificate?

Stated plainly: dulaglutide · eight weeks · 37 °C. I would like to set this up properly once, rather than adjust it repeatedly. My budget is real but not tight, and…

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…

865 questionspeptide-stability

peptide-stability

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

832 questionscoa

coa

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

749 questionspeptidemeter

peptidemeter

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

14 questionsasked by m_haraldsen 38k · 7 months ago

9 votes0 answers2.9k views

Does aggregation show up on HPLC or do I need SEC?

This is a recurring problem with one particular shipping lane rather than a one-off. I suspect the honest answer is that it depends, in which case I would like to…

peptide-stability

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

832 questionshplc

hplc

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

466 questionspurity

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…

788 questionspeptidemeter

peptidemeter

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

14 questionsasked by esben_lykke 15k · 4 months ago

5 votes5 answers11k views

Is a sampling plan from WXT sufficient basis to skip independent testing?

Numbers first: sampling plan · WXT. This is a planning question. I know what my options are; I do not know how to weigh them. What I want is the minimum viable…

coa

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

749 questionsbatch-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…

865 questionsharm-reduction

harm-reduction

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

445 questionspeptidemeter

peptidemeter

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

14 questionsasked by yuki_morishita 19k · 12 months ago

5 votes 5 answers9.1k views

How do I reconcile 98.8% from Janoshik with 96.4% from the supplier?

Numbers first: 98.8% · Janoshik · 96.4%. 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 as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questionsbatch-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…

865 questionscoa

coa

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

749 questionspeptidemeter

peptidemeter

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

14 questionsasked by jonas_ekstrom 18k · 9 months ago

4 votes 5 answers13k views

Is a PeptideMeter rating independent of the vendors it rates?

This is my second independent submission on material from the same supplier. I would like to know whether this claim survives contact with evidence. If the answer is…

peptidemeter

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

14 questionsvendor-vetting

vendor-vetting

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

436 questionsvendor-comparison

vendor-comparison

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

351 questionsasked by coring_risk 17k · 2.2 years ago

4 votes 5 answers9k views

What does a 97.1% purity with a sampling plan attached let me conclude?

Stated plainly: 97.1% · sampling plan. I would like help reading this properly rather than being told what conclusion to reach. I have the full report including the…

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…

788 questionscoa

coa

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

749 questionshplc

hplc

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

466 questionspeptidemeter

peptidemeter

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

14 questionsasked by rukhsana_iqbal 14k · 10 months ago

Janoshik Analytical - Independent Third-Party Testing

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

Submit a sample

GL Biochem (Shanghai) Ltd. - Direct Synthesis

Founded 1998. ISO 9001 and cGMP certified, 1,500+ staff and 200+ patents. The synthesis house behind a great many of the vials that get sent out for testing - batch-specific documentation with every order.

Visit GL Biochem