C# serialize private class member

Question

class Person {     public string m_name;     private int m_age; // << how do I serialize the darn little rat? } 

Simple question yet it seems like a big mess when trying to answer it.
Everyone suggest to use public getter/setter but my app is too big and making a getter/setter for each member would just cause maintainability issues.

Am I forced to create a custom serialization here or is there a magic attribute for such members?
How do I serialize private class members?

Edit #1:
Ok everyone, sorry for the unclarity, I was a bit upset when I wrote this question, it was several hours after trying to find the solution.
Anyway, here are more facts:
1. I'm trying to XML serialize this class. Currently I'm using System.Xml.Serialization.XmlSerializer.
2. I'm serializing into XML to have version compatibility, which as far as I understand binary doesn't offer me that.
3.I was hoping that there's a certain attribute like:

class Person {     public string m_name;     [SerializeThat(ElementName="Age")]     private int m_age; // << how do I serialize the darn little rat? } 

OR (continue of fact #3) an attribute that goes on the class which would look like:

[Serializable(DoPrivate = true, DoProtected = true)] class Person {     public string m_name;     private int m_age; // << how do I serialize the darn little rat? } 

Now, what can I do to achieve it?

Answer 1

Going on the assumption of a typo, I'd like to redirect you to this SO article where the solution is to use a DataContractSerializer instead.

Answer 2

Don't know if you can use DataContract. But with this you could write:

[DataContract] class Person {     [DataMember]     public string m_name;      [DataMember]     private int m_age; } 

The advantage of DataContract that you can serialize private fields and your class doesn't need a default constructor.