What is the difference between the ERCCs and the SIRVs?

ERCC Spike-In Controls (ERCCs, Ambion, Thermo Fisher) allow the user to assess dynamic range, dose response, lower limit of detection, and fold-change response of RNA sequencing pipelines within the limitation of their mono-exonic, single-isoform RNA sequences. Because ERCCs do not contain transcript variants, they cannot be used to measure and evaluate splice variants which represent one of the main challenges of sequencing complex transcriptomes.

In contrast, Lexogen´s SIRV (Spike-In Transcript Variants) isoforms can be used to validate isoform-specific RNA sequencing workflows and to compare experiments by extrapolating the results from the well-defined isoform ground truth of a small fraction of control reads to the sample reads. Within the context of variant detection assessment of dynamic range, dose response, lower limit of detection, and fold-change response is possible as well.

Additionally, the long SIRVs address the need for spike-in transcripts exceeding 2.5 kb. Their range (4 kb to 12 kb) is particularly applicable to validate long-read platforms and RNA-Seq setups.