Targeted mutagenesis by programmable site-specific nucleases like CRISPR typically produce 1-base pair (bp) insertion or deletion (indel) mutations. Although several methods have been developed to detect such 1-bp indels, each method has pros and cons in terms of cost and/or resolution. Heteroduplex mobility assay (HMA) is a traditional technique detecting small base pair differences but it has a limited resolution of mutation size and the band patterns are often complex.