Digital Single-Nucleotide Polymorphism Analysis for Allelic Imbalance

  • Hsueh-Wei Chang
  • Ie-Ming Shih
Part of the Methods in Molecular Medicine™ book series (MIMM, volume 103)


Digital single-nucleotide polymorphism (SNP) analysis is developed to amplify a single template from a pool of DNA samples, thereby generating the amplicons that are homogeneous in sequence. Different fluorophores are then applied as probes to detect and discriminate different alleles (paternal vs maternal alleles or wild-type vs mutant), which can be readily counted. In this way, digital SNP analysis transforms the exponential and analog signals from conventional polymerase chain reaction (PCR) to linear and digital ones. Digital SNP analysis has the following advantages. First, statistical analysis of the PCR products becomes available as the alleles can be directly counted. Second, this technology is designed to generate PCR products of the same size; therefore, DNA degradation would not be a problem as it commonly occurs when microsatellite markers are used to assess allelic status in clinical samples. Last, digital SNP analysis is designed to amplify a relatively small amount of DNA samples, which is available in some clinical samples. Digital SNP analysis has been applied in quantification of mutant alleles and detection of allelic imbalance in clinical specimens and it represents another example of the power of PCR and provides unprecedented opportunities for molecular genetic analysis.

Key Words

Digital molecular genetics mutation allelic imbalance polymerase chain reaction single-nucleotide polymorphism 


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Copyright information

© Humana Press Inc. 2005

Authors and Affiliations

  • Hsueh-Wei Chang
    • 1
  • Ie-Ming Shih
    • 1
    • 2
    • 3
  1. 1.Department of PathologyThe Johns Hopkins University School of MedicineBaltimore
  2. 2.Department of Gynecology and ObstetricsThe Johns Hopkins University School of MedicineBaltimore
  3. 3.The Oncology CenterThe Johns Hopkins University School of MedicineBaltimore

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