Why my RNA absorbance reading shown negative? - (Sep/05/2007 )
QUOTE (aztecan princess @ Sep 12 2007, 05:12 AM)
I think you have a low concentration of RNA. Spectrophotometer in not very sensitive and have many chances of errors. If it’s not calibrates and or your cuvettes are not ok and the RNA is very diluted or have some ethanol contamination, you won’t be able to measured.
Maybe the RNA concentration is low. I will try again with another type of cuvette. Maybe my dilution also made it hard? Because I admit, I do a 50X dilution. 
-cheerioet83-
still depends on your concentration. Diluting 50x a concentrated solution is not a pb, but too much for low-concetrated solution.
If you have tested by electrophoresis, estimate the concentration (roughly) and calculate which dilution factor would give you a decent trustable OD
-fred_33-