Using the MongoDocument class

mongodocumentusage.cs

var mongoCollection = database.GetCollection<MongoDocument>("Dynamic");
 
mongoCollection.Insert(
  new MongoDocument(
    new BsonDocument { 
      { "Name", "A test record" }, 
      { "Date", new DateTime(2013,01,01) }, 
      { "Age", 28 }, 
      { "Complete", false } }));
  
mongoCollection.Insert(
  new MongoDocument(
    new BsonDocument { 
      { "Name", "Another test" }, 
      { "Date", new DateTime(2013,02,02) }, 
      { "Age", 36 }, 
      { "Complete", true } }));
 
var result = mongoCollection.AsQueryable().Where(o => o["Name"] == "A test record").ToList();