Sensitive, multiplex and direct quantification of RNA sequences using a modified RASL assay.

Larman HB, Scott ER, Wogan M, Oliveira G, Torkamani A, Schultz PG
Source: Nucleic Acids Res
Publication Date: (2014)
Issue: 42(4): 9146-57
Research Area:
Immunotherapy / Hematology
Basic Research
Cells used in publication:
B cell, human
Species: human
Tissue Origin: blood
A sensitive and highly multiplex method to directly measure RNA sequence abundance without requiring reverse transcription would be of value for a number of biomedical applications, including high throughput small molecule screening, pathogen transcript detection and quantification of short/degraded RNAs. R NA A: nnealing, S: election and L: igation (RASL) assays, which are based on RNA template-dependent oligonucleotide probe ligation, have been developed to meet this need, but technical limitations have impeded their adoption. Whereas DNA ligase-based RASL assays suffer from extremely low and sequence-dependent ligation efficiencies that compromise assay robustness, Rnl2 can join a fully DNA donor probe to a 3'-diribonucleotide-terminated acceptor probe with high efficiency on an RNA template strand. Rnl2-based RASL exhibits sub-femtomolar transcript detection sensitivity, and permits the rational tuning of probe signals for optimal analysis by massively parallel DNA sequencing (RASL-seq). A streamlined Rnl2-based RASL-seq protocol was assessed in a small molecule screen using 77 probe sets designed to monitor complex human B cell phenotypes during antibody class switch recombination. Our data demonstrate the robustness, cost-efficiency and broad applicability of Rnl2-based RASL assays.