Vector concentration following maxiprep - (Feb/16/2008 )
hey guys, after i maxiprep my vector using the kit from qiagen, i got a concentration of roughly 1400 ng/ul. however, a few days later, i took another OD260 reading of the same preparation and found that the concentration had decreased to half of what it was mentioned earlier. any ideas what's going on? thanks.
-qkchen-
QUOTE (qkchen @ Feb 16 2008, 02:20 PM)
hey guys, after i maxiprep my vector using the kit from qiagen, i got a concentration of roughly 1400 ng/ul. however, a few days later, i took another OD260 reading of the same preparation and found that the concentration had decreased to half of what it was mentioned earlier. any ideas what's going on? thanks.
1.4ug/ul is a good concentration.
In your situation, I suspected your vector may be contaminated by RNA.
RNA is easily degraded,so the 2nd concentration is much lower.
-glcui-
What were the 260/280 and 260/230 ratios?
-zek-
QUOTE (zek @ Feb 18 2008, 02:19 AM)
What were the 260/280 and 260/230 ratios?
The OD260/268 was 1.47 and OD260/230 was 1.66. What kind of insights do these provide? I just know that the OD260/280 is for purity of DNA. Thanks again.
-qkchen-
The 260/280 ratio is to check protein contamination, must be ~1.6-1.8. The 260/230 ratio is to check RNA contamination as far as I know and must be above 2. Maybe it is a good idea top check the DNA on agarose gel after the prep.
-zek-