The effects of freeze-drying on bacteriophage T4

The damage by freeze-drying to bacteriophage T4 was analysed in order to locate the site and the mechanism of damage. As a result of freeze-drying of bacteriophage T4, its head coat was damaged so as to lead to the loss of the DNA and emptying of the head. The tail assembly was generally undamaged and the freeze-dried phage preserved the biological activities concerned with absorption and injection (inhibition of host colony formation, inhibition of induction of beta-galactosidase, induction of changes in the potassium content in the host bacteria).The 2 mechanisms by which the freeze-drying damages the phage arc: osmotic shock, which occurs mainly during the resuspension of the FD phage, and the drying per se, i.e., the removal of water from the head protein.