[Serializable]
public class SCMng
{

[XmlElement("SC")]
public ObservableCollection<SC> SCCollection { get; set; }

[XmlIgnore]
public SC SCPreview { get; set; }

public SCMng()
{
   this.SCCollection = new ObservableCollection<SC>();
   this.SCPreview = new SC();
}

public void SaveMD(string pPath)
{
   Directory.CreateDirectory(Path.GetDirectoryName(pPath));

   if (System.IO.File.Exists(pPath))
       System.IO.File.Delete(pPath);

   var ser = new XmlSerializer(typeof(SCMng));
   using (var fs = new FileStream(pPath, FileMode.OpenOrCreate))
      ser.Serialize(fs, this);
}

}

SCMng fooBar = new SCMng();

public void Save(){
    this.fooBar.SaveMD(AppDomain.CurrentDomain.BaseDirectory + @"new.xml");
}