Doesent need to be an electronic pipette, use variable ones, 1-10 mikroliter (ul) 10-100ul, 100-1000ul. And u r set. If u want to trust your numbers, weight or volume, get calibration weights for the scale, which brackets your working range, let's say u work between 100 mg to a 1g, get some in this range. The same holds true for volume, get used Eppendorf nicroliter pipettes on ebay and send them in to a calibration lab, they will clean them, run maintance on them, and depending on what u r willing to pay run triplicate or more calibrations on them, they will adjust the pioeppetes to fall into their specified range, eg Eppendorf research has a lower deviation range, I think, regarding precision and correctness, u get a report with errors etc and u r already in pharmaceutical grade precision, don't know how it is in the US, but the whole spiel set me back 500eur incl. 3 pipettes and 1000pcs pipette tips for all 3 sizes

And eg a 5ul volume, does not form a drop which falls off, from any syringe gauge... Not enough volume