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260nm/280nm ratio of DNA after maxi preparation - why <1.5 (Sep/02/2008 )

HALLO,

Have an urgent question. after DNA maxi preparation the absorbance ratio is round 1,5. This, i think, is too low.

I checked for possible protein contamination with BCA assay => no PROTEIN

additionally i checked for endotoxin, agarosegel looks also pretty ...

don´t know what the reason for this could be.

Does anyone of you have any suggestions? I reached the point where I can´t help myself.

-moljul-

I wouldn't worry about this ration too much. My DNA rations are normally around 1.8, but often between 1.5 and 2. I never had any problems. I would just go ahead and use it. If you have problems you can always do another prep.

-UGA80-

QUOTE (UGA80 @ Sep 2 2008, 06:56 PM)
I wouldn't worry about this ration too much. My DNA rations are normally around 1.8, but often between 1.5 and 2. I never had any problems. I would just go ahead and use it. If you have problems you can always do another prep.


the problem i had was that i injected DNA into mice and all died immediately. therefore i´m afraid that something was wrong with my DNA prep.
i just got paranoid because of that!

-moljul-

QUOTE (moljul @ Sep 3 2008, 08:43 AM)
QUOTE (UGA80 @ Sep 2 2008, 06:56 PM)
I wouldn't worry about this ration too much. My DNA rations are normally around 1.8, but often between 1.5 and 2. I never had any problems. I would just go ahead and use it. If you have problems you can always do another prep.


the problem i had was that i injected DNA into mice and all died immediately. therefore i´m afraid that something was wrong with my DNA prep.
i just got paranoid because of that!


I don't suppose it's got particular high GC content, that can swing it down (i use high AT content DNA and it's sometimes well above 2 and still OK)

-dancom-

QUOTE (dancom @ Sep 3 2008, 05:00 PM)
QUOTE (moljul @ Sep 3 2008, 08:43 AM)
QUOTE (UGA80 @ Sep 2 2008, 06:56 PM)
I wouldn't worry about this ration too much. My DNA rations are normally around 1.8, but often between 1.5 and 2. I never had any problems. I would just go ahead and use it. If you have problems you can always do another prep.


the problem i had was that i injected DNA into mice and all died immediately. therefore i´m afraid that something was wrong with my DNA prep.
i just got paranoid because of that!


I don't suppose it's got particular high GC content, that can swing it down (i use high AT content DNA and it's sometimes well above 2 and still OK)



thanks for supply.

-moljul-