1. Noncontinuously Binding Loop-Out Primers for Avoiding Problematic DNA Sequences in PCR and Sanger Sequencing 
Kelli Sumner, Jeffrey J. Swensen, Melinda Procter, Mohamed Jama, Whitney Wooderchak-Donahue, Tracey Lewis, Michael Fong, Lindsey Hubley, Monica Schwarz, Youna Ha, Eleri Paul, Benjamin Brulotte, Elaine Lyon, Pinar Bayrak-Toydemir, Rong Mao, Genevieve Pont-Kingdon, D. Hunter Best 
The Journal of Molecular Diagnostics 
Volume 16, Issue 5, Pages (September 2014)
DOI: /j.jmoldx
Copyright © 2014 American Society for Investigative Pathology and the Association for Molecular Pathology Terms and Conditions

2. Figure 1
Sample containing the MEN1 rs polymorphism (not shown); sequences from c.240_259. A: Amplification with a normal forward primer; the 4-bp deletion (black bar), c.249_252delGTCT, was undetectable. B: Amplification with a loop-out forward primer showed a clearly discernable 4-bp deletion, c.249_252delGTCT.
The Journal of Molecular Diagnostics  , DOI: ( /j.jmoldx )
Copyright © 2014 American Society for Investigative Pathology and the Association for Molecular Pathology Terms and Conditions

3. Figure 2
Amplification of ASS1 exon 9. Top: Amplification through the problematic region with a traditional primer. The sequencing signal decreased to zero shortly after the G-rich region. Bottom: Amplification with a loop-out forward primer removed the problematic region, resulting in consistent sequence signal throughout the read.
The Journal of Molecular Diagnostics  , DOI: ( /j.jmoldx )
Copyright © 2014 American Society for Investigative Pathology and the Association for Molecular Pathology Terms and Conditions