Description
CORALL mRNA-Seq V2
Get the best sequencing data with CORALL mRNA-Seq V2. The kit enables fast and cost-efficient generation of stranded, UMI labelled, and unique dual indexed libraries with adjustable insert size.
Performance
CORALL mRNA-Seq V2 is a fast and flexible whole transcriptome sequencing kit with exceptional performance on low input RNA samples.
Exceptional Gene Detection Across a Wide Range of Input Amounts
CORALL mRNA-Seq V2 delivers excellent gene discovery rates across a wide range of RNA input amounts for long and medium library lengths (Fig. 1).
Figure 1 | Gene discovery rates. A) Gene discovery rates for libraries with long length (average size 550 bp) and B) medium length (average size 350 bp). 1 ng, and 1000 ng Universal Human Reference RNA (UHRR) were used as input for poly(A) selection and library preparation using CORALL mRNA-Seq V2. Libraries were sequenced on Illumina® NextSeq500 (2×150 bp). The number of detected genes is plotted against the number of reads mapping uniquely to exons (calculated with featureCounts).
Excellent Reproducibility and Sensitivity
Correlation analysis of CORALL mRNA-Seq libraries from 1 ng total RNA input prior to poly(A) selection reveals excellent reproducibility for libraries of all sizes (Fig. 2).
Figure 2 | Excellent reproducibility between replicates for low input RNA. Correlation analysis between replicates for CORALL mRNA-Seq with 1 ng UHRR input for libraries with A) medium length (average size ~350 bp) and B) long length (average size ~550 bp). Libraries were sequenced on Illumina® NextSeq500 (2×150 bp).
Excellent Isoform Detection Across a Wide Range of Input Amounts
Lexogen’s Spike-in RNA Variant controls (SIRVs) are a set of 69 synthetic RNA molecules that mimic transcript isoform complexity. CORALL mRNA-Seq V2 authentically reproduces the expected coverage of the highly complex SIRV6 locus with 16 transcript isoforms and 2 anti-sense transcripts (Fig. 3). Thus, CORALL is ideal for isoform discovery and alternative splicing applications, even at inputs as low as 1 ng of total RNA (prior to poly(A) selection).
Figure 3 | Coverage transcript isoforms of SIRV6 across RNA input amounts. Lexogen’s SIRV-Set 3 was spiked into Universal Human Reference RNA at of 1 % of the mRNA fraction. Total RNA amounts of 1000 ng, 100 ng, 10 ng, and 1 ng were used for poly(A) selection and CORALL mRNA-Seq V2 library preps for generation of libraries with long insert sizes. Libraries were sequenced on Illumina® NextSeq500 (2×150 bp). Reads were mapped to the SIRV reference genome and visualized in condensed coverage profiles on gene level (upper panel). The exon-intron structure of all 18 transcripts of the SIRV6 locus is shown in the lower panel (with antisense transcripts in blue). The coverage generated by CORALL mRNA-Seq V2 is shown as overlay for four different input amounts.
Performance on Blood Samples
Total RNA from mammalian blood can be obtained by minimally invasive sampling and is therefore the most commonly used sample to study diseases in cohorts or patients. However, whole blood RNA is comprised of highly abundant undesired RNA species, such as ribosomal RNA (rRNA), accounting for ~80 – 90 % of total RNA, and globin mRNA, representing 30 – 80 % of all mRNAs.
As a consequence, the majority of reads in mRNA-Seq experiments from blood samples maps to globin (Fig. 4). While globin can be removed from fresh blood samples during the RNA extraction step, this process is not efficient when blood samples need to be stored of frozen prior to processing.
The combination of CORALL mRNA-Seq with an additional RiboCop depletion step for removal of rRNA and globin mRNA provides a convenient workflow to process also stored blood samples. This workflow frees up sequencing space for mRNAs of interest (Fig. 4) and leads to a significant increase in gene detection (Fig 5 A and B).
Figure 4 | CORALL mRNA-Seq V2 with an additional rRNA and globin depletion step efficiently removes globin mRNA from human whole blood RNA for mRNA-Seq applications. RNA was extracted from human donor whole blood. Whole blood RNA was enriched for polyadenylated transcripts using the Poly(A) Selection Kit included in the CORALL mRNA-Seq V2 bundles. One set of samples was additionally depleted with RiboCop HMR+Globin. Libraries were prepared with the CORALL RNA-Seq V2 Library Prep and sequenced on NextSeq500 (1×75 bp). Reads were mapped against the human reference genome (GRCh38.95) and reads mapping to rRNA (blue) and globin (purple) were calculated.
Figure 5 | Increased gene detection for CORALL mRNA-Seq with additional rRNA and globin depletion. A) The number of detected genes per number of reads uniquely mapping to exons (FeatureCounts) was plotted for the samples shown in Figure 4. B) Bar plot illustrating the number of detected genes for the samples shown in Figure 4 at 1 M reads /sample, normalized to Counts Per Million (CPM) at a threshold of CPM > 1.
Superior End-to-End Coverage
Table 1 | CORALL RNA-Seq V2 workflow specifications
| Feature | Specification | Benefit | ||
| CORALL RNA-Seq V2 (stand-alone Kit) | CORALL mRNA-Seq V2 with Poly(A) Selection | CORALL Total RNA-Seq V2 with RiboCop | ||
| Input RNA quantity | 0.1 ng – 100 ng | 1 ng – 1000 ng | 1 ng – 1000 ng | Supports the widest input range available on the market, delivers consistent library output over the full input range |
| RNA types | Total RNA | Poly(A) RNA | Ribo-depleted RNA | Supports all Whole Transcriptome RNA-Seq Applications |
| RNA quality | All qualities, including degraded RNA, FFPE | High-quality RNA (RIN > 8) | All qualities, including degraded RNA, FFPE | Supports all RNA qualities, high sensitivity and high-quality results for difficult material and FFPE samples |
| Workflow time* | 4.5 hours | 5.5 hours | 6 hours | Time-saving workflow with less steps, from sample to sequencing-ready library in one day |
| Kit reaction sizes | 24, 96, 384 | 96, 384 | 24, 96 | Scalable for evaluation, adoption and high-throughout applications |
| Technology | Fragmentation-free library prep using displacement-stop technology | Poly(A) selection by hybridization / capture and CORALL library prep | Hybridization / capture rRNA-depletion without enzymatic digestion and CORALL library prep | – Fragmentation-free workflow – No second strand synthesis – No adaptor titration, less adapter-dimers – Excellent inherent strandedness (> 99 %) |
| Unique Dual Indexing (UDI) | All CORALL RNA-Seq V2 Kits and Bundles contain 12 nt UDI Sets. | Maximized sequencing output on all instruments | ||
| Unique Molecular Identifiers (UMIs) | All CORALL RNA-Seq V2 Kits and Bundles contain built-in UMIs. | Supports identification and removal of PCR duplicates for all sample types and quantities without additional purchases | ||
| Automation Capability | All CORALL RNA-Seq V2 workflows can be automated on liquid handlers. | Supports high-throughput applications | ||
* Workflow time is based upon incubation times and expected times for hands-on-steps. Actual workflow time may vary.
CORALL mRNA-Seq Library Prep Kit
Product Flyer
User Guide for CORALL V2 – update 12.07.2023
User Guide for PCR Add-on and Reamplification Kit V2 – update 08.08.2023
User Guide for Poly(A) Selection Kit – update 13.12.2022
Lexogen UDI 12 nt Unique Dual Index Sequences – update 26.03.2021