NanoDrop 1000 Spectrophotometer
The NanoDrop 1000 Spectrophotometer is a small, simple to use, single sample spectophotometer that analyses 1 ul directly, using surface tension to create a path. There is no need to dilute your sample into a plate well or cuvette. Pipet one drop and read. There is no fee to use the instrument and no sign-up. Bring your own pipettes/tips and keep the area clean. Be sure to wipe off your last sample so it is not dried on for the next user.
Things to consider: UV-Vis cannot distinguish RNA from DNA and contaminating nucleic acids often cause an overestimation of concentration. The ratios 260 nM : 280 nM, and 260nM : 230nM tell us about the shape of the absorbance peak. Both ratios are around 2.0 in a clean nucleic acid sample. Lower 260:280 indicates protein or phenolic contamination.
Low 260:230 indicates some contaminants absorbing in the UV. Ethanol, guanidine, some buffers and some polysaccharides absorb in those short wavelengths.
