The differential hybridization technique hasbeen widely used to identify genes that are dif-ferentially expressed.However,this approachhas several drawbacks.First,the screeningprocedures are rather labor-intensive and time-consuming.Second,the amount of phageDNAs transferred onto the two filters may notbe equivalent,which leads to an inaccurate se-lection of a positive clone.Third,isolation ofphage DNA is slow and cumbersome.Here,aPCR based differential screening method that The differential hybridization technique hasbeen widely used to identify genes that are dif-ferentially expressed. Hoster, this approach has several drawbacks. First, the screening procedures are rather labor-intensive and time-consuming. Second, the amount of phageDNAs onto onto the two filters may notbe equivalent, which leads to an inaccurate se-lection of a positive clone.Third, isolation ofphage DNA is slow and cumbersome. Here, aPCR based differential screening method that