PCR with the fluorogenic DNA stain SYBR® Green I

Abstract

SYBR® Green I is a sensitive stain for DNA in agarose gels (Ref. [1]). Its enormous increase in fluorescence upon binding to double-stranded DNA has led to its use in monitoring the accumulation of product during PCR (Ref. 2, 3). However, SYBR Green I inhibits unmodified PCR reactions. In this article, I show that using smaller amounts of SYBR Green I and supplementing the MgCl₂ in the reaction relieves this inhibition. In addition, PCR products labeled with SYBR Green I can be easily detected in the reaction tube with a fluorescence plate reader or in unstained agarose gels after electrophoresis.