Journal of Chromatography A, 1083 (2005) 179–184 Microchip capillary gel electrophoresis using programmed field strength gradients for the ultra-fast analysis of genetically modified organisms in soybeans Yun-Jeong Kim a , Joon-Seok Chae b , Jun Keun Chang c , Seong Ho Kang a,∗ a Department of Chemistry, Chonbuk National University, Jeonju 561-756, South Korea b Bio-safety Research Institute and College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, South Korea c Digital Bio Technology, SKC Central Research Institute Room 511, Suwon 440-301, South Korea Received 15 March 2005; received in revised form 25 May 2005; accepted 1 June 2005 Available online 20 June 2005 Abstract We have developed a novel method for the ultra-fast analysis of genetically modified organisms (GMOs) in soybeans by microchip capillary gel electrophoresis (MCGE) using programmed field strength gradients (PFSG) in a conventional glass double-T microchip. Under the programmed electric field strength and 0.3% poly(ethylene oxide) sieving matrix, the GMO in soybeans was analyzed within only 11 s of the microchip. The MCGE-PFSG method was a program that changes the electric field strength during GMO analysis, and was also applied to the ultra-fast analysis of PCR products. Compared to MCGE using a conventional and constantly applied electric field, the MCGE-PFSG analysis generated faster results without the loss of resolving power and reproducibility for specific DNA fragments (100- and 250-bp DNA) of GM-soybeans. The MCGE-PFSG technique may prove to be a new tool in the GMO analysis due to its speed, simplicity, and high efficiency. © 2005 Elsevier B.V. All rights reserved. Keywords: Chip technology; GMO; Fast analysis; Programmed field strength gradients 1. Introduction Biotechnology or gene transfer enables us to use important genes or characteristics from one organism and to place the genes with advantageous characteristics into another species. Transgenesis refers to the transfer of a gene or genes from one species into another host species. The newly introduced genes encode a new protein that gives the desired quali- ties in the host plant, animal or bacteria. Generally, this genetically modified organism (GMO) expresses new spe- cific properties such as herbicide tolerance, insect resistance and productivity increase [1,2]. While the demand for com- mercial use of GMO has continuously increased due to its multiple advantages such as agricultural productivity, there is still a lot of controversy about GMO due to its potential risks ∗ Corresponding author. Tel.: +82 63 270 3421; fax: +82 63 270 3408. E-mail address: shkang@chonbuk.ac.kr (S.H. Kang). to human health and world ecology. Thus, both European and Japanese legislation have recently introduced require- ment of the obligatory labeling of foodstuffs produced from GMOs with a threshold of 1 and 5%, respectively, of GM material in a non-GM background [3–6]. Therefore, accu- rate and fast analytical methods for the quantification of GMOs in foodstuffs and/or for products containing GMO are required. There are various detection methods for the identifi- cation of GMOs including protein-based methods, SDS gel electrophoresis, Western blot analysis, enzyme-linked immunosorbant assay (ELISA) [7,8], nucleotide-base ampli- fication methods [9], detection of specific promoter and terminator sequences [10], capillary electrophoresis (CE) [11,12] and real-time PCR [9]. Among these techniques, slab gel electrophoresis, CE and real-time PCR method are most commonly used for the detection of GMO-specific amplification products. CE exhibits a faster separation with 0021-9673/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.chroma.2005.06.002