Test for null values in C#

If I do something like:

DataSet ds = GetMyDataset();

try
{
    string somevalue = ds.Tables[0].Rows[0]["col1"];
}
catch
{
    //maybe something was null
}

Is there a good way to check for null values without using the try/catch? It's just that I don't care if the value in "col1" is null, OR if "col1" didn't exist, OR if there were no rows returned, OR if the table doesn't exist!

Maybe I should care? :) Maybe try/catch is the best way of approaching this but I just wondered if there was another way to do it?

Thanks!