Insert have sac1 site and i need to clone in pbi121 in place of GUS and i have option at 5 prime end in vector as well as insert but there is no compatible at 3 prime end in vector as well as in insert becoz pbi121 have only sac1 site and 3 prime side and another left side at 3 prime which is also present in insert. Can i use T 4 dna polymerase via bluntingblunting at 3 prime end? Suggest and tell the way?