Good day! Please Register or Log in to view the hidden image! We bought Gentamicin Sulfate as antimicrobial agent against E.Coli in 2 ml capacity ampules. It has got inscription in russian language indicating its name, concentration (4 %) and etc. Please Register or Log in to view the hidden image! I wanted to know the molecular weight and formula of this substance and in internet I found the controversial information. Here http://www.scbt.com/datasheet-203334.html it is written its formula C60H125N15O25S, and molecular weight: 1488.79. The exact name is also provided- Gentamicin Sulfate. But here http://www.chemblink.com/products/1405-41-0.htm other formula is provided C21H43N5O7.H2SO4 and molecular weight is equal to 575.67. The name is also provided there, however a bit different: Gentamycin sulfate. But the melting point for both substances are exactly the same: 218-237 °C. So, could you please tell me, what substance do I have in those ampules? I need their exact molecular weight and formula. Please Register or Log in to view the hidden image!