Dear Saeid

• In short yes they are more than suitable in grade
• However, for RT qPCR unless your primers are > 30bp ecen standard desalted purity are of sufficient quality: I routinely use all such primers at standard desalted grade
• For longer primers PAGE purified or a version of HPLC are used simply to ensure that that your full length primer is present @ > 90%. In this instance standard purity leads to a higher percentage of N-1 and N-2 truncated primers such that your full length might only approximate to ~ 70%
• But apart from elongated primers all levels of purity will work for RT qPCR

Thank you