Abstract
Freeze-drying is used as a method to stabilize proteins. The process itself may however cause protein unfolding and denaturation, but the risk is reduced if a stabilizing agent is added prior to freeze-drying. Here chicken antibody (IgY) preparations were freeze-dried in the presence or absence of lactose, sucrose and threalose as stabilizing agent at 0.3, 0.06 and 0.012M. The activity of freeze-dried IgY batches in the absence of stabilizing agent was similar before and after freeze-drying, but decreased slowly during eight weeks at 37°C. Addition of disaccharide resulted in a preserved activity after eight weeks in 37°C, compared to samples with no sugar added. The results were similar irrespective of sugar type and concentration (0.012-0.3M). This shows that IgY freeze-dried in the presence of disaccharide is very stable and a method to reduce the cost and simplify transport, storage and use of avian antibodies.
