freeze thaw cycling is the risk, not one freeze. that is my read of it anyway
#storage-coldchain 2026-03-21
Saturday34 messages6 participantstimes are UTC
Highlights from this day
- salt_bridge — the door swings four or five degrees every time somebody opens it. the back barely moves 20:15
- salt_bridge — do i need to worry about light exposure or is that overthinking 20:21
- warsaw_vial — the practical risk in winter shipping is freezing, and in summer it is heat. plan for the season you are in 21:18
- elm_escalates — light exposure matters much less than temperature for these. i still keep them in the carton 22:04
a liquid cold pack tells you it was above freezing, not that your vial cooked
genuine question i left a reconstituted vial out overnight once, sent it for testing out of curiosity, it came back fine
gel packs
lyophilised powder is genuinely robust. a warm transit is far less likely to matter than people fear, happy to be corrected
power cut with the door shut for a few hours is fine. a full fridge holds temperature surprisingly well
[edited]i freeze aliquots and have had them test fine afterwards. others here would not do it and i understand why
freezing reconstituted peptide is the one thing this channel has never agreed on
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genuine question do you keep the unopened vials and the in-use one in the same place
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genuine question i keep everything at the back of the middle shelf, never the door
i have never had a lyophilised vial fail after a warm transit and i have had some bad ones
log it
the door swings four or five degrees every time somebody opens it. the back barely moves
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while im here reconstituted solution is the fragile part. that is where the cold chain actually earns its keep
do i need to worry about light exposure or is that overthinking
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flying with vials, hand luggage or checked
door shelf or back of the fridge
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freeze debate again
genuine question a cooler with two gel packs held under eight degrees for eleven hours on a drive
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i would bin it
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buy a thermometer. mine reads 5.6 on the door and two degrees lower at the back
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i log the fridge temperature daily and the room has never let me forget it
lyophilised at room temp for 25 days in transit, worried or not
do you log the fridge temperature or is that too far
parcel sat in a hot mailbox for 9 hours, is it dead
buy a thermometer
does the fridge in a hotel room count as a fridge
back of the fridge
the practical risk in winter shipping is freezing, and in summer it is heat. plan for the season you are in
mon 4.1 / door 7.2
tue 4.0 / door 7.8
wed 4.2 / door 6.9
thu 3.9 / door 7.4
fri 4.1 / door 8.1 <- shopping day
sat 4.3 / door 7.0
sun 4.0 / door 6.8nobody here can tell you a vial is safe. we can tell you what has and has not survived for us
a few hours at room temperature is almost certainly nothing. a week is a different conversation
light exposure matters much less than temperature for these. i still keep them in the carton
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if you are worried after a bad transit, test it. that is what the testing channels are for
power cut for 4 hours, fridge stayed shut, am i fine