using System;

using System.IO;

using System.Runtime.Serialization;

using System.Runtime.Serialization.Formatters.Binary;

​

public class TestParent

{

    public int SomeField;

}

​

[Serializable]

public class SomeChild : TestParent

{

    public int SomeSerializedField;

}

​

public class Program

{

    public static void Main()

    {

        var someChild = new SomeChild() {

            SomeField = 5,

            SomeSerializedField = 10

        };

        IFormatter formatter = new BinaryFormatter();  

        Stream stream = new MemoryStream();  

        formatter.Serialize(stream, someChild);

        stream.Seek(0, SeekOrigin.Begin);

        SomeChild reproduced = (SomeChild)formatter.Deserialize(stream);

        Console.WriteLine(string.Format("Original:   SomeField={0} SomeSerializedField={1}", someChild.SomeField, someChild.SomeSerializedField));

        Console.WriteLine(string.Format("Serialized: SomeField={0} SomeSerializedField={1}", reproduced.SomeField, reproduced.SomeSerializedField));

    }

}