I am working on E.coli bacteria after growing bacteria in LB I centrifuge it at 7000 then resuspend it and add 2 ml deionized sterile water and 19 microliters gold. In the confocal machine, there is no fluorescence. Why?
Is it being diluted too much with the 2 ml of water? Can you concentrate the sample and put it under a coverslip on a slide to check your fluorescence? Once you have that initial confirmation you can dilute it further and move forward.