a slightly collapsed cake is cosmetic. a puddle in the bottom is not
U-100 syringe: 1 unit = 0.01 ml
10u = 0.10 ml
25u = 0.25 ml
50u = 0.50 ml
100u = 1.00 ml
mg drawn = ml drawn x mg/ml🔥13😂1👍11
#reconstitution 2025-10-03
Friday35 messages5 participantstimes are UTC
Highlights from this day
- batch_bandit — a slightly collapsed cake is cosmetic. a puddle in the bottom is not 14:10
- vienna_vial — 20mg in 2ml is 10mg/ml. 1mg is 10 units, 2mg is 20 units, easy 14:26
- deadspace — lyophilised powder is far more robust than people think. it is the solution that is fragile, your mileage will differ 15:11
- tarpit_tam — i have never once regretted using a rounder number and a slightly bigger volume, i think 15:47
is there any reason not to just always use 2ml
weighing the vial before you reconstitute is the only way to catch an underfill
my 10mg vial weighed 11.4g on the jewellery scale, is that wrong
weigh it first
the vacuum will pull it in. let it. fighting it is how you get a face full of aerosol
is the meniscus reading actually a real source of error or am i overthinking
is a slightly cloudy solution ever ok or is that always a bin it
20mg in 2ml is 10mg/ml. 1mg is 10 units, 2mg is 20 units, easy
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benzyl alcohol is what makes it bacteriostatic. it is about 0.9% typically
if the maths gives you 13.7 units, change the volume. do not try to hit 13.7, n of 1 obviously
nope, redo it
it should be completely clear with no floaters. cloudy means stop
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do i swirl for a specific length of time or just until its clear
how much do i lose to dead space with a 30G pin
the last few units are a real loss. i accept it rather than tilting the vial and drawing air
i keep a spare vial of bac water in the fridge purely so i never rush the maths
i was wrong about this last year: it is fine to draw cold, it just stings more going in
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lyophilised powder is far more robust than people think. it is the solution that is fragile, your mileage will differ
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you can absolutely just always use 2ml, and honestly most of us should, ask me again in a month
30mg in 3ml is 10mg/ml, so 5mg is 50 units. half the barrel, feels like a lot but its right, i have it written down somewhere
gross powder mass is not net peptide. water and counterion are in that number, someone check my working
i have never once regretted using a rounder number and a slightly bigger volume, i think
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10mg in 2ml is 5mg/ml. so 0.5mg is 0.1ml which is 10 units on a u100
*mg/ml, obviously
label the date too. you will not remember which vial is which by week 17
how long after reconstituting before its actually dissolved
what do you do with the last 50 units when you cant draw them cleanly
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sorry to jump in if the powder is on the stopper, tap it down before you add anything. it will still dissolve either way
bacteriostatic water for anything multi-use. sterile water has no preservative in it at all
if i add 5ml to a 2mg vial what concentration am i actually at
check your maths
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read it at eye level
it foamed. is it ruined
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aim the diluent at the glass wall, not at the powder. it goes in gentler
if you draw up with a bigger pin and inject with a fresh one you lose a bit more to dead space
i write the mg/ml on the vial with a sharpie the moment i reconstitute it