someone explain dead space to me like I have not read a paper in years
someone explain dead space to me like I have not read a paper in years. If this has been answered properly somewhere, link me and I will delete.
If your calculation produces a fraction of a unit, the concentration is wrong for your dose. Change the water volume until the numbers land on whole units.
Bacteriostatic water contains benzyl alcohol as a preservative, which is what makes repeated entry into the same vial reasonable. Plain sterile water has no preservative.
The lyophilised cake displaces a small volume, so the true concentration is very slightly lower than the arithmetic suggests. It is a fraction of a percent and it is dwarfed by fill tolerance.
If two or three other people have done the same thing we might actually learn something. Alone it is an anecdote.
best — the order this archive was captured in
The arithmetic in full: concentration is mass over volume, so 10mg into 2mL gives 5mg/mL. A U-100 syringe is graduated at 100 units per millilitre, so 2mg is 2 divided by 5 millilitres, which is 40 units.
What is written on the vial right now?
How many mg in the vial and how many mL are you adding?
Aim the stream down the wall of the vial rather than into the cake. Reconstitution is a solubility problem, not a mixing problem, and mechanical shear does nothing helpful.
Disagree with the "more water is safer" framing. It is not safer, it is just a different number to divide by.
Disagree with the "more water is safer" framing.
nadia_kjaer has the units point exactly right. They are a volume on the barrel and nothing else.
Adding more water does not change how much peptide is in the vial. It changes the concentration, which changes the volume you draw for the same amount. That is the entire relationship.
Same. I got this wrong once, caught it because the units looked absurd, and have written on every vial since.
Research-use-only material is not approved for human use, so treat everything in this thread as arithmetic about solutions rather than instructions for a person.