What is the use of tRNA? - (Nov/12/2007 )
I am trying to do gel shift assay with RNA oligos and cell extracts (that I think will carry RNA-binding proteins). I have the recipe of a couple of different RNA bidning buffer. One of the buffer has yeast tRNA in it. One has tRNA and BSA in it. What exactly is the role of yeast tRNA or BSA in RNA binding buffer? Do they reduce non-specific RNA-protein interactions?
BSA and tRNA are usually used to prevent the RNA oligos from binding to the tube or well walls and not being available for binding to the protein. In addition, any contaminating RNases, phosphatases (that strip off a kinased 32P label), or phosphodiesterases in your cell extracts will have tRNA to attack in addition to your sample.
Thanks for the information, I don't have label degaradtion or stikcing problem. But I have non-specific binding. Looks like I have to proceed in different direction.