How to do Datatable Merging ?

i have two datatables,

DataTable dt1=obj.SomeFunction();
DataTable dt2=obj.SomeFunction();

// I put an iteration on dt1 to select some value from dt2 e.x

foreach(DataRow row in dt1.Rows)

{
string s=dt1.row["ColumnName"].ToString();

var newquery = from b in dt2.AsEnumerable()
               let somevariable= b.Field<string>("DataColumn").ToString()
                      where (s== somevariable)

                      select new
                      {
                          somevariable

                      };
//here i want to add each itteration into list<> and then. add the list<> to dt1
}