gistfile1.cs

var request = (HttpWebRequest)WebRequest.Create(this.Url);
request.Accept = "application/json";
request.ContentType = "application/json";
request.Method = "POST";
using (var writer = new StreamWriter(request.GetRequestStream()))
{
	writer.Write(this.PostBody);	
}
var response = request.GetResponse();
string responseString = null;
using(var stream = response.GetResponseStream())
{
	using(var reader = new StreamReader(stream)) 
	{
		responseString = reader.ReadToEnd();
	}
}