mL to Units on a U-100 Syringe
On a U-100 syringe, 1 mL equals 100 units, so units = mL × 100 and mL = units ÷ 100.
Published · Updated · PepCalcs editorial team · Editorial policy
The scale
'U-100' describes the barrel graduation, not the contents. A U-100 barrel is divided so that a full 1 mL reads 100 units regardless of what liquid is inside it. The scale is purely a volume scale for reconstituted peptide solutions.
Units = mL × 100
mL = units ÷ 100
Common readings
- 0.05 mL = 5 units
- 0.1 mL = 10 units
- 0.25 mL = 25 units
- 0.5 mL = 50 units
- 1.0 mL = 100 units
U-100 vs U-40
U-40 barrels read 40 units per millilitre, so the same 0.1 mL reads 4 units instead of 10. If a calculator's unit output disagrees with another tool by a factor of 2.5, a U-40/U-100 mismatch is the usual explanation. Check the barrel marking before trusting any unit figure.
Reading partial marks
Most 1 mL U-100 syringes are graduated in 1- or 2-unit increments; 0.3 mL and 0.5 mL barrels are graduated more finely and are easier to read for small volumes. If your calculated volume falls between marks, increasing the diluent volume raises the volume per draw and moves the reading onto a printed graduation.