Try something like this:
Stopwatch stopWatch = (StopWatch)DataTable.Rows["StopWatch"];
EDIT (after comment) ===========
Let me ask you this - why are you trying to save an entire object when you only need one or two properties? Can't you just change the column from a
in your db and make it easier on yourself? In fact, all you really need is the
property, and you should be gold.