I need to use a photometer, so i have Cary Agilent and i would like to know what kind of cuvettes and its dimensions and volume i have to order. It's about RNA and DNA samples. Which are you recommended?
check the manual for whichever spectrophotometer you have and the cuvette holders available. Not all "Cary Agilents" are the same (model name or number would have helped). Find the smallest cuvettes you can that are UV transparent. There are even some cuvettes that can turn your spec into a nanodrop (I have one).
Typically you should get down to 50 uL normal cuvettes and if you have the funding 3 uL for the nanodrop cuvette.