Storing binary objects in SQL Server with LINQ

You will need to convert your List<object> to a byte[]. You don't need Linq specifically but I assume you are using Linq To Sql? Before storing your object in the property that should contain the binary you need to convert it to a byte[]. Here is some example code to do what you need (Source Link):

// Convert an object to a byte array
private byte[] ObjectToByteArray(Object obj)
{
    if(obj == null)
        return null;
    BinaryFormatter bf = new BinaryFormatter();
    MemoryStream ms = new MemoryStream();
    bf.Serialize(ms, obj);
    return ms.ToArray();
}

// Convert a byte array to an Object
private Object ByteArrayToObject(byte[] arrBytes)
{
    MemoryStream memStream = new MemoryStream();
    BinaryFormatter binForm = new BinaryFormatter();
    memStream.Write(arrBytes, 0, arrBytes.Length);
    memStream.Seek(0, SeekOrigin.Begin);
    Object obj = (Object) binForm.Deserialize(memStream);
    return obj;
}