Searching inside the genes.
Why long-read sequencing?
Single-cell sequencing has been key in identifying cell subpopulations, helping researchers develop more precise treatments for various cancers and immune diseases that require a cell-level understanding of the patient’s genetics. However, most single-cell platforms have so far been limited to short reads that cannot cover a complete RNA transcript and thus make researchers lose valuable data found in isoforms and ambiguous sequences.
CART Cell Therapy is perhaps one of the most impactful applications of single-cell sequencing so far. For the first time in history, in January of last year it cured Alyssa, a 13-year-old who used to suffer from acute lymphoblastic leukemia (ALL). By matching the full sequence of T-Cell receptors of individual cells with their transcriptome, doctors can access high-resolution insights into adaptive immune response. Integrating long-read sequencing at the single-cell level, they could track clonal populations to monitor the persistence of CAR-T cells in the patient or analyze complex genetic variations like isoforms that may influence the effectiveness and safety of the therapy.
On the other hand, there’s a disease that affects an older yet larger population. Genes like APOE are highly influential in the risk of developing Alzheimer’s, but when it comes to potential new therapies, it’s essential to go one level deeper. Splicing can lead to several RNA isoforms per gene, each of which could have a different, sometimes opposing, function. The APP gene, for instance, encodes the beta-amyloid precursor protein in Alzheimer’s disease, and is expressed in 5 different RNA isoforms encoding 5 different proteins. Also in Alzheimer’s, the TNFSF12-219 isoform is significantly upregulated in disease cases while the TNFSF12-203 isoform is significantly upregulated in controls.
Last but not least, when it comes to ambiguous sequences, the T2T Consortium has only recently been able to sequence human telomeres by leveraging long-read sequencing technologies. Long regarded as junk, it’s been discovered that some long noncoding RNAs may actually represent 5′ UTRs of coding genes — Biology is full of puzzles that only long read sequencing can help resolve.
“We still don’t know how the genome works” — Thomas Sudhof, Nobel Laureate, at the 2024 Synbiobeta conference.
Breaking down the barriers of single-cell long-read sequencing
The ArgenTag Single-cell RNA Library Kit, is the first single-cell kit for long-read sequencing. It converts the mRNA from individual cells into full-length tagged cDNA that is directly sequenceable by long-read platforms like ONT or PacBio. Its smart barcoding technology withstands the noise inherent to long-read sequencing technologies so that no barcode whitelist is required, speeding up the reads assignment to one day.
The ArgenTag single-cell RNA library kit for long-read sequencing is device free and allows the study of single cells in 1 mt beanch.
Agile, versatile and cost-effective. Single cells are partitioned into individual microwells in a portable microfluidic chip without the need for any special equipment, and their mRNA is captured using magnetic beads. The chip allows the analysis of up to 10,000 single cells or nuclei in 5 hours of wet-lab work.
The ArgenTag team has been working with researchers from Mount Sinai, Chan Zuckerberg BioHub, NYU Langone Health, and the Institute of Medical and Clinical Ophthalmology in Basel, who have been pleasantly surprised by the capabilities of the kit and the new research opportunities it unlocks.
"Isoforms are opening a new paradigm; the ArgenTag kit hands researchers the key to do experiments that were previously unthinkable." - First results with KOLs exceeded expectations.
An early access opportunity is available to try the ArgenTag Library Kit. The waitlist is open on this website.
A new era of long-read single-cell sequencing has begun.
By Sofia Sanchez