Shotgun phage display cloning

Shotgun phage display cloning is a useful tool for studying interactions be tween bacterial and host proteins. Libraries are constructed by cloning ran domly fragmented prokaryotic DNA into phagemid-vectors. Theoretically, thes e libraries will consist of phages that together display all proteins encod ed by the bacterial genome. Selecting a gene III-based library, made from S taphylococcus aureus DNA, against IgG and fibronectin resulted in 20-40% po sitive clones after two pannings. Increasing the number of fusion proteins per phage particle by using gene VIII-based display, increased the frequenc y of correct clones to 75-100%.