When amps are used in hospitals they use filtered needles. I'm not saying something will go wrong if you don't but there is a chance you can get glass in your syringe. You will lose a very small amount of gear the first time using a filtered needle but just re use the same needle through the cycle and you will only lose that initial amount. Plus you notice when using say one ml amps you draw it out and get a little over that amount in your syringe. It is set up to lose a little through a filter.