The Comparison of the Effectiveness of a Modified Conformation Sensitive Gel Electrophoresis with Denaturing High Performance Liquid Chromatography

Background: Several methods have been developed for detection of sequence variation in genes and each has its advantages and disadvantages. A disadvantage of them is that the simpler, cost-effective methods are commonly perceived as being less sensitive in their detection of sequence variation, whereas those with proven sensitivity have a requirement for complex or expensive laboratory equipment. In this context, we undertook improvements to the conformation sensitive gel electrophoresis (CSGE) method which provides a cost-effective approach to mutation detection and compared the results with scanning carried out using denaturing high performance liquid chromatography (DHPLC) which utilises a dedicated analyser. Methods: We designed PCR primers to amplify the seven protein-coding exons of the human SPP2 gene which encodes secreted phosphoprotein 24 (spp24) such that the amplified products included the immediately-adjacent intronic regions. Five improvements were made to the CSGE method that was used to the scan the PCR-amplified DNA. The scanning was then repeated using DHPLC and the results were compared. Results: Using CSGE, a single nucleotide polymorphism was discovered in exon 2 and another in intron 2 of the gene. Re-scanning of the same regions by DHPLC detected no additional sequence polymorphisms. Conclusion: With modification of the original protocol, CSGE is capable of providing a simple and cost-effective approach to the detection of DNA sequence polymorphisms that appears to be comparable in sensitivity to DHPLC.