Detection of Genetically Modified Soybeans in Miso by Polymerase Chain Reaction and Nested Polymerase Chain Reaction

TZU-MING PAN* AND TSUNG-WEI SHIH

Department of Agriculture Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 106, Taiwan, ROC

(Received: August 29, 2002; Accepted: October 18, 2002)

ABSTRACT

   In this study, we used polymerase chain reaction (PCR) to detect genetically modified Roundup Ready soybean (RRS) in miso.  Several different DNA extraction methods had been tested. The CTAB method published by Lipp et al. and a commercial kit, Nucleospin Food, were used, because they had the most appropriate performance for miso sample. Four pairs of primers specific for the inserted genes and crop endogenous genes in RRS were applied in PCR. Using these primers, the method showed a false-negative result for the miso sample during a later period. When another more sensitive method, nested-PCR had been used, we obtained false-negative result for the sample in later fermentative stage. Since PCR and nested-PCR can not yield to positive results, using these two methods to detect transgenic components in miso is not efficient.

Key word: RRS, Miso, PCR, nested-PCR