High-throughput genotyping of single nucleotide polymorphisms with rolling circle amplification

Area of Science:

• Genetics
• Molecular Biology
• Biotechnology

Background:

• Single nucleotide polymorphisms (SNPs) are crucial for complex trait and pharmacogenomic studies.
• Existing SNP databases necessitate simple, robust, and scalable genotyping methods.
• Current methods often require preamplification of target DNA, adding complexity.

Purpose of the Study:

• To develop an inexpensive, simple, robust, and scalable SNP genotyping method.
• To enable high-throughput SNP scoring directly from human genomic DNA.
• To meet the demands of automated genetic analyses.

Main Methods:

• A solution-based, microtiter plate method utilizing allele discrimination by ligation of open circle probes.
• Rolling circle amplification of the signal using fluorescent primers.
• Circularization of probes occurs only when the 3' base is complementary to the SNP.

Main Results:

• Achieved 100,000-fold discrimination against mismatched probes.
• Successfully genotyped 10 SNPs from 192 genomic DNA samples in a high-throughput format.
• Demonstrated genotyping sensitivity using as little as 1 ng of genomic DNA, detecting single molecules of circularized probe.

Conclusions:

• The method is compatible with homogeneous formats, suitable for automation.
• Assaying small amounts of genomic DNA directly simplifies the process.
• Meets requirements for automated, high-throughput SNP scoring in genetic research.