Get SERIOUS about your cell-free DNA

SRSLY - our Single Reaction Single-stranded DNA Library Prep Kit. SRSLY is a simple and efficient ligation-based single-stranded DNA library preparation method that is engineered to produce complex libraries from 1 nanogram of input cell-free DNA. SRSLY recovers complete double-stranded DNA molecules, even when they contain nicks, plus single-stranded DNA molecules inaccessible to most NGS prep kits. Did we mention it does all of this, from sample to sequencer, in under 3 hours without altering the native ends of cell-free DNA molecules? Seriously.

No matter your sample type, we got you - whether biologically degraded nucleic acid samples, DNA sheared in vitro, synthetic oligonucleotides or probes, and even first-strand cDNA. Perform targeted enrichment and other downstream techniques with the most complex library possible.

Cell-free DNA applications for the SRSLY NGS library preparation kit include any Illumina sequencing based approach, ranging from liquid biopsy, prenatal or infectious disease testing, and personalized medicine. Other SRSLY applications include oligo QC and RNAseq workflows.


How SRSLY Works


SRSLY works in a one-step combined phosphorylation/ligation step that simultaneously prepares template DNA molecules for ligation without end-polishing and simultaneously ligates proprietary Illumina-compatible adapters.

Product Specifications

  • From DNA to sequence-ready Illumina® library in under 3 hours

  • Optimized for 1 ng of cell-free DNA with input concentrations as low as 50 pg/µl

  • Options available for single and dual-indexing, as well as unique molecular identifier (UMI) incorporation



How SRSLY Compares


Methods - Sequencing libraries were generated from two healthy cfDNA extracts. The results between SRSLY and 3 commercially available library preparation methods were compared.

SRSLY Libraries Produce High DNA Yields - allowing users more flexibility with downstream manipulations prior to sequencing


SRSLY Post Index PCR Yields and Mapping Statistics Compared to Commercial Kits


SRSLY Libraries Map with Accuracy and Retain More Short Fragments - Mapping performance of SRSLY is on par with the best commercial kits on the market. SRSLY goes above and beyond other kits by capturing a higher percentage of reads with short inserts (30-100 bp) to help researchers leverage valuable biology encoded in short cfDNA fragments.

SRSLY Libraries Produce Uniform GC Coverage

SRSLY Generates Complex Libraries - Retaining native termini with SRSLY does not mean sacrificing library complexity. SRSLY ensures you get the most out of your 1 ng input by creating complex libraries on par with the best commercial kits on the market.



Biological Discovery, SRSLY

The majority of DNA fragments extracted from blood plasma cfDNA are centered around 167 base-pairs (bp) in length with a recognized sawtooth pattern of 10.4 bp that is the result of DNase I cleaving the exposed minor grove of nucleosome-bound DNA. In addition, cfDNA derived from blood plasma contains a valuable minority of short length sized DNA fragments (30-100 bp) that harbor footprints of transcription factors, other DNA binding proteins, mitochondrial DNA, and microbial derived DNA, all of which adds a valuable layer of detail to cfDNA sequence data.


SRSLY enables biological discovery by its ability to capture an increased proportion of sub-nucleosome sized fragments and by its ability to retain the native ends of DNA fragments. dsDNA preps, like NEB and TaKaRa, retain little data in the sub-nucleosome size range and end-polish terminal information away (above). The commercially available ssDNA method, available from Swift Biosciences, employs a molecular method which artificially shifts all data 10 bp shorter and abolishes the biologically relevant sawtooth pattern (left).


Want More SRSLY?


SRSLY cell-free DNA White Paper


SRSLY Oligo QC White Paper


R-SRSLY RNA-SEQ white Paper