precise quantificatin of genomic DNA from different sources

[Brian C. Freeman]

Need Help: I have problem in quantification of genomic DNA from different
cell lines. The DNA samples have been treated with RNase A,
phenol-chloroform, and the OD260/280 are higher than 1.8. Loading the same
amount of DNA(based on OD260 measuring)  from different samples in agarose
gel, however, gives a significantly different fluorecent intensity. Should
I trust the result from OD measuring or from agarose gel?