Smart-Seq2

Smart-Seq2

Method Category: Transcriptome > RNA Low-Level Detection

Description: For Smart-Seq2, single cells are lysed in a buffer that contains free dNTPs and oligo(dT)-tailed oligonucleotides with a universal 5'-anchor sequence. RT is performed, which adds 2–5 untemplated nucleotides to the cDNA 3′ end. A template-switching oligo (TSO) is added, carrying 2 riboguanosines and a modified guanosine to produce a LNA as the last base at the 3′ end. After the first-strand reaction, the cDNA is amplified using a limited number of cycles. Next, tagmentation is used to construct sequencing libraries quickly and efficiently from the amplified cDNA.

Pros:
  • As little as 50 pg of starting material can be used
  • mRNA sequence does not have to be known
  • Improved coverage across transcripts
  • High level of mappable reads
Cons:
  • Not strand-specific
  • No early multiplexing1
  • Transcript length bias, with inefficient transcription of reads over 4 Kb2
  • Preferential amplification of high-abundance transcripts
  • Purification step may lead to loss of material
  • Could be subject to strand-invasion bias3