SMARTer Human TCR a/b Profiling Kit

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Sequencing reads on target and correlation of clonotype count data for varying sample input amounts

Sequencing reads on target and correlation of clonotype count data for varying sample input amounts. Panel A. Percentages of sequencing reads that map to CDR3 regions in either TCR-α (blue) or TCR-β (purple) or that represent off-target reads (gray). The experimental protocol was performed on three different amounts of peripheral blood RNA: 10 ng, 100 ng, and 1,000 ng. Panel B. Correlation of clonotype count data for 100 ng input RNA vs. 1,000 ng input RNA. Pearson (R) and Spearman (ρ) correlation coefficients are included.

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Assessing the sensitivity and reproducibility of the SMARTer approach

Assessing the sensitivity and reproducibility of the SMARTer approach. The experimental protocol was performed in replicate on PBMC RNA samples spiked at varying concentrations (10%, 1%, 0.1%, 0.01%, and 0.001%) with RNA obtained from a homogenous population of Leukemic Jurkat T cells (TRAV8-4-TRAJ3, TRBV12-3-TRBJ1-2 clonotype). Panel A. Correlation between concentration of spiked-in Jurkat RNA and number of TRBV12-3-TRBJ1-2-specific sequence reads. Numbers along the X-axis indicate serial-diluted concentrations of spiked-in Jurkat RNA (by mass): 1 = 10%; 2 = 1%; 3 = 0.1%; 4 = 0.01%; 5 = 0.0.01. Count data for TRBV12-3-TRBJ1-2-specific sequence reads were normalized by subtracting the number of corresponding reads obtained for negative control samples consisting of unspiked PBMC RNA. Normalized count data were then Log₁₀ transformed. Circles and triangles correspond to experimental replicates for each sample concentration. Results of linear regression analysis are indicated in the upper right region of the graph. Panel B. Count data, signal-to-noise ratios, and statistical analysis for TRBV12-3-TRBJ1-2-specific sequence reads obtained from spiked RNA samples. Signal-to-noise ratios were generated using the mean counts of TRBV12-3-TRBJ1-2-specific sequence reads for each pair of experimental replicates. Rows highlighted in yellow include concentrations of spiked-in Jurkat RNA for which statistically significant elevations in TRBV12-3-TRBJ1-2-specific sequence reads were detected relative to background counts observed for unspiked negative control RNA samples.

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Library preparation workflow and PCR strategy for TCR profiling using the SMARTer approach

Library preparation workflow and PCR strategy for TCR profiling using the SMARTer approach. Panel A. Reverse transcription and PCR amplification of TCR subunit mRNA sequences. First-strand cDNA synthesis is primed by the TCR dT Primer and performed by an MMLV-derived reverse transcriptase (RT). Upon reaching the 5′ end of each mRNA molecule, the RT adds non-templated nucleotides to the first-strand cDNA. The SMART-Seq v4 Oligonucleotide contains a sequence that is complementary to the non-templated nucleotides added by the RT, and hybridizes to the first-strand cDNA. In the template-switching step, the RT uses the remainder of the SMART-Seq v4 Oligonucleotide as a template for the incorporation of an additional sequence on the end of the first-strand cDNA. Full-length variable regions of TCR cDNA are selectively amplified by PCR using primers that are complementary to the oligonucleotide-templated sequence (SMART Primer 1) and the constant region(s) of TCR-α and/or TCR-β subunits (TCR a/b Human Primer 1). A subsequent round of PCR is performed to further amplify variable regions of TCR-α and/or TCR-β subunits and incorporate adapter sequences, using TCR Primer 2 and TCR a/b Human Primer 2. Included in the primers are adapter and index sequences (read 2 + i7 + P7 and read 1 + i5 + P5, respectively) that are compatible with the Illumina sequencing platform. Following purification, size selection, and quality analysis, the TCR cDNA library is ready for sequencing. Panel B. Semi-nested PCR approach for amplification of TCR-α and/or TCR-β subunits. The primer pairs used for the first round of amplification capture the entire variable region(s) and most of the constant region(s) of TCR-α and/or TCR-β cDNA. The second round of amplification retains the entire variable region(s) of TCR-α and/or TCR-β cDNA, and a smaller portion of the constant region(s). The anticipated size of final TCR library cDNA (inserts + adapters) is ~700–800bp.