WCF Interface from another assembly

Hi

I'm still pretty new to WCF, so maybe this is a stupid question.

I have a WCF service and was wondering if it were possible to reference different DLL's with service contracts in them and make them accessible through the same service?

So I would have one dll with something like this in it:
[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)]
  public partial class MyTestClass : IMyTestClass
  {
 
  public string _TestSalesOptions()
  {
  return "SalesOpstion says Halo!";
  }
  }

[ServiceContract]
  public interface IMyTestClass
  {
  [OperationContract]
  string _TestSalesOptions();
  }


Now... would I be able to reference this dll in my main service and add a endpoint??
I've spend the better part of the morning googling and I haven't found any results to what I'm trying to do. Maybe it can't be done? Maybe we should rather create separate small services?