Higher resolution microplate array diagonal gel electrophoresis: application to a multiallelic minisatellite

Area of Science:

• Molecular Biology
• Genetics
• Biotechnology

Background:

• The 5' polymorphic region of the insulin gene (INS) contains a variable number of tandem repeats (VNTR) locus.
• Accurate sizing of these VNTR alleles is crucial for genetic studies.

Purpose of the Study:

• To develop and validate a high-throughput, precise method for sizing insulin gene VNTR alleles.
• To evaluate the utility of microplate array diagonal gel electrophoresis (MADGE) for VNTR analysis.

Main Methods:

• PCR amplification of the INS gene VNTR locus.
• Analysis of PCR products using 96-well open-face MADGE gels with Duracryl polyacrylamide.
• Visualization using Vistra Green intercalating dye and a FluorImager 595 system.
• Allele sizing using Phoretix software and Microsoft Excel.

Main Results:

• Achieved precise sizing of class I alleles (641-843 bp) with resolution of single tandem repeat differences.
• Demonstrated reliable allele identification even with small differences, using heteroduplexes as confirmation.
• Enabled simultaneous electrophoresis of up to 1,000 samples in 90 minutes.
• Eliminated the need for end-labeled primers, reducing costs and complexity.

Conclusions:

• MADGE provides a cost-effective and efficient method for high-throughput VNTR allele sizing of the insulin gene.
• This technique overcomes throughput limitations of traditional electrophoresis systems for minisatellite analysis.
• The developed method ensures accurate and reliable genetic analysis of the INS VNTR locus.