How to manage DBNull Values propertly

Hi,
I retrieve some rows from DB and populate a DataTable; then I transform this DataTable to a List of Objects.
If some cells of the rows has DBNULL values, how is the proper way to manage this?
1: Updating DB not supporting Null values
2: Iterating DataTable and converting DBNull values to ""
3: Checking this DBNull values on the function that transforms DataTable onto List of Objetcs
4: ??????
Thanks.

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Ok, solved. What about using
If(datarow("field") Is DBNull.Value, "", datarow("field")
as param passed on the constructor.
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