UMI

UMI

Method Category: Transcriptome > RNA Low-Level Detection

Description: Unique molecular identifiers (UMI) are molecular tags that are used to detect and quantify unique mRNA transcripts. In this method, mRNA libraries are generated by fragmentation and reverse-transcribed to cDNA. Oligo(dT) primers with specific sequencing linkers are added to the cDNA. Another sequencing linker with a 10 bp random label and an index sequence is added to the 5' end of the template, which is amplified and sequenced. Sequencing allows for high-resolution reads, enabling accurate detection of true variants.

Pros:

• Can sequence unique mRNA transcripts
• Can detect transcripts occurring at low frequencies
• Transcripts can be quantified based on sequencing reads specific to each barcode
• Can be applied to multiple platforms to karyotype chromosomes

Cons:

• Targets smaller than 500 bp are preferentially amplified by polymerases during PCR

• Kivioja T., Vaharautio A., Karlsson K., Bonke M., Enge M., et al. (2012) Counting absolute numbers of molecules using unique molecular identifiers. Nat Methods 9: 72-74

Related Publications

1. Macosko E. Z., Basu A., Satija R., Nemesh J., Shekhar K., et al. (2015) Highly Parallel Genome-wide Expression Profiling of Individual Cells Using Nanoliter Droplets. Cell 161: 1202-1214
2. Shugay M., Britanova O. V., Merzlyak E. M., Turchaninova M. A., Mamedov I. Z., et al. (2014) Towards error-free profiling of immune repertoires. Nat Methods 11: 653-655
3. Islam S., Zeisel A., Joost S., La Manno G., Zajac P., et al. (2014) Quantitative single-cell RNA-seq with unique molecular identifiers. Nat Methods 11: 163-166