public static object DeSerializeFromXmlString(System.Type typeToDeserialize, string xmlString) {
    byte[] bytes = System.Text.Encoding.UTF8.GetBytes(xmlString);
    MemoryStream memoryStream = new MemoryStream(bytes);
    System.Xml.Serialization.XmlSerializer xmlSerializer = 
        new System.Xml.Serialization.XmlSerializer(typeToDeserialize);
    return xmlSerializer.Deserialize(memoryStream);
}

Example
[Test]
public void GetBigList() {
    var textRepository = ObjectFactory.GetInstance<ITextRepository>();
    List<BrandAndCode> brandAndCodeList = textRepository.GetList(...);
    string xml = SerializeToXmlString(brandAndCodeList);
    Console.Out.WriteLine("xml = {0}", xml);
     var brandAndCodeList2 = DeSerializeFromXmlString(typeof (BrandAndCode[]), xml);
}

//csharp/4817