GLPHubglpresearchhub.com
Read-only archive. GLP Research Hub is a static community record — nothing here is for sale, no account is needed, and no vote you cast is counted. Why?
Archived. This submission is more than a year old. Votes and new comments are closed, and some of the advice in it may have been superseded — check the community wiki for the current version.
2.3k
c/coldchain·posted 1 year ago by u/sequence_checker

[Question] data logger — what am I missing here

Question Slow Clap ×3 Sourced ×2

The title is the whole question — data logger — what am I missing here — but here is why I am asking.

Lyophilisation removes the water that drives most degradation pathways. That is why the dry cake is comparatively robust and the reconstituted solution is not.

Seasonality, which the source-page lane tables show clearly once you look for it.

The same origin, destination and carrier can differ by several days between February and August, and the temperature exposure differs by much more than the transit time suggests. A lane that is uneventful in winter is the same lane that generates the summer threads.

Two practical consequences. First, compare like months when you compare lanes. Second, ask which lines a supplier holds in regional stock — a shorter leg in July is worth more than any amount of packaging.

On loggers, since I was sceptical and then bought one.

A small transit logger costs a fraction of a vial and records the whole journey rather than the moment of arrival. What I learned from three of them: my lane is far more stable than I assumed, the one excursion I did capture was on a weekend, and the arrival-temperature guessing I had been doing was worthless.

If you are going to argue about cold chain, argue from a chart. It is a one-off purchase and it ends the speculation permanently.

If somebody has the same thing measured a different way, post it next to mine and we will see whether they agree.

2,570 up / 254 down91% upvoted38 commentsid pj26tb11 Mar 2025

38 comments

24 in this archive, depth 5

best — the order this archive was captured in

u/priya_guerrero331 points·1 year ago

A stability statement is only meaningful with its conditions attached: temperature, duration, light exposure, and whether it covers powder or solution. Ask which.

replysharereportpermalink
u/milos_vestergaard482 points·1 year ago

A transit temperature logger records a distribution, and time above a threshold matters as much as peak temperature. That is the argument for logging rather than guessing.

replysharereportpermalink
u/isabela_nilsen163 points·1 year ago

Regional stock changes the question rather than answering it: shorter lanes mean less exposure and fewer variables, which is why the warehouse question is worth asking before ordering in summer.

replysharereportpermalink
u/intent_to_treat173 points·1 year ago

You cannot infer potency from a temperature record. The record tells you what happened to the box; only a test tells you what happened to the material.

replysharereportpermalink
u/coldchain_karenMOD86 points·1 year ago

Left up and added to the lane table. Origin, destination and month were all included, which is all we ask.

replysharereportpermalink
u/kian_solberg67 points·1 year ago

a warm gel pack tells you the pack failed, not that the material did

replysharereportpermalink
u/jarno_adeyemi32 points·1 year ago

a warm gel pack tells you the pack failed, not that the material did

kian_solberg is right that the pack failing is not the material failing. Two separate claims.

replysharereportpermalink
[deleted]43 points·1 year ago

[deleted]

replysharereportpermalink
u/sequence_checkerOPresearch peptides138 points·1 year ago

What was the packaging — rigid outer, gel packs, anything insulating?

replysharereportpermalink
u/priya_guerrero90 points·1 year ago

Yes — a logger in the box turns a fortnight of speculation into a chart.

replysharereportpermalink
u/sequence_checkerOPresearch peptides61 points·1 year ago

Correcting myself above: the transit was 16 days, not the figure I posted. Same conclusion, wrong number.

replysharereportpermalink
u/sterile_field_steph165 points·1 year ago

Is this a line they hold in regional stock or is it shipping from origin?

replysharereportpermalink
u/zeynep_ndiaye72 points·1 year ago

Where in the fridge is it sitting now?

replysharereportpermalink
u/anjali_tamm23 points·1 year ago

How many days in transit, and which month?

replysharereportpermalink
u/anders_karlsen8 points·1 year ago

Right, and asking what the stability statement was written against is one line of email that reframes everything.

replysharereportpermalink
u/usb_logger_ursula-6 points·1 year ago

light matters more than people think for some of these

replysharereportpermalink
u/maren_sorensen1 point·1 year ago·edited

That is the ambient temperature at the destination, not the temperature inside the box. The logger measures the second one.

replysharereportpermalink
u/sequence_checkerOPresearch peptides6 points·1 year ago

Right, and asking what the stability statement was written against is one line of email that reframes everything.

Disagreeing with this line only: freezing a reconstituted vial is not a safe default.

replysharereportpermalink
u/noor_cardoso32 points·1 year ago

Put a logger in three consecutive orders. Two never went above the range at all and the third spent four hours warm on a Friday. Cost me almost nothing to stop wondering.

replysharereportpermalink
u/brigade_detector22 points·1 year ago

Small fix — refrigerated, not frozen, once it is in solution.

replysharereportpermalink
u/plain_titration_202429 points·1 year ago

ask what storage condition the stability statement was written against

replysharereportpermalink
u/aleksi_eriksen65 points·1 year ago

Gel pack fully liquid on arrival, powder tested 99.6% against a claimed 99.0% afterwards. The pack had done its job for as long as it was designed to.

replysharereportpermalink
u/jarno_karlsen91 points·1 year ago

Once in solution, the relevant risks are hydrolysis, aggregation and, for some sequences, oxidation. Refrigeration slows all three; freezing a solution introduces a separate risk at the ice interface.

replysharereportpermalink
u/analog_alphabet38 points·1 year ago

a summer lane and a winter lane are different lanes

replysharereportpermalink
Permalinked branches
Deep branches get their own page so a single reply chain can be linked and read on its own.
About c/coldchain

Temperature and stability in the real world: what an excursion actually costs you, why lyophilised powder is far more forgiving than reconstituted solution, how to read a logger CSV, and how to photograph a failed shipment so the conversation with the vendor is short.

27kmembers
95submissions
Oct 2023created
submissions / month, last year
Sponsored

Sigma-Aldrich Standards

Certified reference materials for peptide identity and purity work.

sigmaaldrich.com
c/coldchain rules
  1. Excursion claims need a logger trace or a photo taken at unboxing. "It felt warm" is not data.
  2. No tracking numbers, ever. They identify you and the recipient.
  3. Stability claims need a source or an explicit "this is my guess" label.
  4. Independent community. Nobody here sells anything, and anyone who tries is banned.
  5. Not medical advice. Describe what you did; never prescribe to a stranger.
  6. Claims need evidence. Batch numbers, dated screenshots, independent test reports, or a citation.
  7. No referral links, discount codes or affiliate URLs. Permanent ban, no appeal.
  8. No contact handles, wallet addresses or tracking numbers — they identify people.
  9. Be recognisably decent. Disagree hard, insult nobody.
Moderators
Volunteers. Unpaid, unaffiliated, and reachable through modmail only.
Before you read on

Several compounds discussed on GLP Research Hub are sold for research use only and are not approved for human use anywhere. Nothing here is medical advice and none of it is written by your clinician. If a post reads like an instruction, treat it as a description of what one stranger did.