Spectrophotometric measurement of RNA quantity - In what should RNA be diluted for measurement at 260nm (Jun/14/2002 )
I'm using the Trizol protocol for total RNA extraction. When quantitating the RNA (diluted in highly purified water) I sometimes get low 260/280 ratios. The product troubleshooter suggests that this may be due to dilution of RNA in water and not TE. Does anyone know what this TE is or have a good suggestion regarding what solutions should be used for diluting the RNA when measuring at 260nm?
TE is a solution of Tris and EDTA 10:1.
You can prepare a solution 10 mM Tris-HCl + 1 nM EDTA at different pHs.
EDTA is always pH 8.0, and Tris can be at 7.4, 7.6 or pH:8.0.
Personnally, i don't use TriReagent or Trizol anymore, because there is too many possibility of poor yields because of many steps and contamination with DNA and proteins. If you can, use commercial kits like Quiagen RNAeasy, which doesn't use phenol, is very quick, and gives good 260/280 ratios.
Sorry, it is 1mM EDTA and not 1 nM... (10:1)