protocol88

Man I feel your pain so hard. Had this exact same issue last month with a cheap supplier and ended up throwing out two whole vials because the rubber fragments fell right inside.

protocol21

Try bevel up and press the heel of the bevel against the rubber first before pushing the point in. Sounds crazy but it makes a huge difference in cutting cleanly.

assayhead

Yeah exactly using thirty one gauge fixed insulin needles. Is there a trick to avoid the punching effect without switching to separate draw needles.

stackgal27

That happens to me whenever my hands shake and I twist the syringe while pushing down. You have to go straight down with zero lateral pressure or the edge of the metal shears right through.

noderoom

Some manufacturers just use really cheap synthetic rubber that behaves like old chewing gum instead of self healing silicone. Sucks when you get a bad batch of glassware.

quietx74

Are you using insulin syringes with fixed needles by any chance. Those things are usually twenty nine or thirty one gauge and the steel is so thin it acts like a literal paper punch on tough stoppers.

salthands

Switch to insulin syringes with removable needles if you can find them or just use a separate drawing needle like an eighteen gauge to pierce the stopper first then swap to the tiny one for dosing.