Temperature loggers worth the money — setting out what I have, and where I think it stops being reliable.
Something about temperature loggers worth the money does not reconcile and I would like a second pair of eyes before I decide which half is wrong.
Two sources, both reputable, giving figures that cannot both be right unless they are measuring different quantities. My suspicion is that they are, and I cannot see how.
Everything in the opening post holds. The case it does not cover is the one I have.
A temperature indicator that has tripped tells you a threshold was crossed. It does not tell you for how long, and duration is most of what determines whether anything happened.
Somebody will have a better source than mine, and I hope they post it.
I will take the caveat as seriously as the claim, which is the point of putting it there.
This follows post #3 rather than contradicting it.
Something worth flagging about temperature loggers worth the money: the strongest-sounding claims in this thread are the ones with no source attached, which is the usual pattern and not a coincidence.
I read post #3 twice before replying, because I had assumed the opposite.
Summer routes and winter routes are genuinely different problems, and a supplier that changes its packing between them is doing something rather than nothing.
Reading it again, the caveat matters more than the finding.
Where I part company with post #7, and it is a narrow parting.
If you are not going to be there, arranging a secure delivery point is worth more than any packing decision the supplier can make.
The interesting part of this is the exception, and I do not understand the exception.
Suppliers that reship after a documented excursion without argument are doing something commercially costly, and it is worth recording when they do.
Worth one more sentence than it usually gets.
Temperature excursions: brief excursions above 8 °C are tolerable for most compounds. Hours to a day at room temperature is usually acceptable. Days to weeks at room temperature risks degradation.
I have deliberately not rounded that, because the rounding is where the argument starts.
Domestic refrigeration: most lyophilised peptides are stored at 2–8 °C (35–46 °F). That is standard refrigerator temperature. Check your refrigerator's actual temperature; some are warmer than the label.
Written from notes rather than memory, which is why the numbers are specific.
Post #12 answers the question as asked. The question underneath it is different.
For anyone finding this later: the short answer on temperature loggers worth the money is that it depends on one thing, and the rest of the thread is people identifying which thing.
I read post #10 twice before replying, because I had assumed the opposite.
I keep a log for temperature loggers worth the money specifically because my memory of it turned out to be systematically wrong in one direction. Six weeks of notes cost nothing and settled it.
Shipment during summer or to hot climates: consider shipping to a cold-storage facility rather than to home if temperatures will be high. Alternatively, time shipment to arrive when you can refrigerate immediately.
That is a description of practice, not a recommendation of it.
A phase-change pack holds a defined temperature while it changes state and then behaves like anything else. A gel pack starts cold and warms continuously. They are different tools for different transit lengths.
It is one reading of the data and not the only reasonable one.
Lyophilised material is far more tolerant of a warm transit than a solution would be, which is why suppliers ship dry and why an excursion is not automatically a loss.
Small point, but it is the one that usually catches people.
Grateful for the specificity. Vague answers to this question are what sent me looking.
Helpful, and short, which on this subject is harder than long.
Where I part company with post #20, and it is a narrow parting.
I would put moderate confidence on the mainstream reading of temperature loggers worth the money and no more. That is not scepticism for its own sake; it is where the sourcing actually stops.
Post #20 is the version of this I will quote in future. One addition.
Freeze-thaw: some peptides tolerate freezing; others do not. Check your compound's labelling. Generally, repeated freeze-thaw is worse than single freeze-thaw.
Assessing an excursion: if a package sat at room temperature for a time, visual inspection (cloudiness, discoloration, particles) can alert you to problems. Not visible does not mean not damaged, but visible problems are a reason to contact the supplier.
I have said this before in a thread nobody could find, so it is worth repeating.
Temperature loggers in the parcel exist and are occasionally used for high-value shipments. They are the only thing that turns an argument about transit into a record.
The uncertainty is in the assumption, not in the calculation.
Building on post #23 rather than restating it.
Temperature logging: devices that record temperature over time let you confirm cold chain was maintained. Useful if a shipment was delayed or if you are concerned about excursion.
Old habit: I write down the expected answer before I calculate it.
This settles it for me, at least until somebody posts a reason it should not.
Before the thread moves on from temperature loggers worth the money — what is the sample size behind the claim? I am not being difficult; I have seen the same figure quoted from an n of four and from an n of four hundred.
A phase-change pack holds a defined temperature while it changes state and then behaves like anything else. A gel pack starts cold and warms continuously. They are different tools for different transit lengths.