how to fill dropdown list from extra huge datatable?

private void FillPlaintiff()
   {

       //declare connection by pass connection string from web.config
       SqlConnection sqlcon = new SqlConnection
           (ConfigurationManager.ConnectionStrings["SystemConn"].ConnectionString);
       //declare sql statment  as astring variable

       SqlCommand sqlcom = new SqlCommand();
       sqlcom.Connection = sqlcon;
       sqlcom.CommandType = CommandType.StoredProcedure;
       sqlcom.CommandText = "proc_SelectPlaintiff";



       DataTable ds = new DataTable();
       //fill data set with data adabter that contain data from database
    //   sad.Fill(ds);
       sqlcon.Open();
        SqlDataAdapter sad = new SqlDataAdapter(sqlcom);

        sad.Fill(ds);

       ddlPlaintiffName.DataSource = ds;
       ddlPlaintiffName.DataBind();
       ddlPlaintiffName.Items.Insert(0, "--select  --");
       sqlcon.Close();

   }