In C# how can I serialize a List to a byte[] in order to store it in a DB field?

I know how to serialize to a file on the disk, but how do I just serialize to a variable?

Here is how I serialized to the disk:

            List<int> l = IenumerableofInts.ToList();
            Stream s = File.OpenWrite("file.bin");
            BinaryFormatter bf = new BinaryFormatter();
            bf.Serialize(s, lR);
            s.Close();

I'm sure it's much the same but I just can't wrap my head around it.