Table 1.

Low-input library preparation methods tested in this study

Technique	Reference/Commercial supplier	Salient details	Reported DNA input range	Sequencing platform compatibility
Accel-NGS® 2S (Accel-2S)	Swift Biosciences, Inc.	5-step process of DNA repair, adapter ligation and PCR amplification. 5 purification steps.	0.01 – 1000 ng	Illumina
Modified Illumina method (Bowman)	Kingston Lab [36]	4 step procedure of end-repair, A-tailing, adapter ligation and PCR. 4 purification steps.	0.1 – 1000 ng	Illumina
HTML-PCR (HTML)	Camilli lab [37]	4-step procedure of end-repair, poly-C-tailing, poly-G-adapter oligo ligation and PCR. 4 purification steps.	0.01 – 100 ng	Illumina
SeqPlex™	Sigma Aldrich, Inc.	3-stage process of semi-random primed pre-amplification, PCR amplification, and primer removal. 2 purification steps.	0.1 – 1 ng	Agnostic (subsequent library prep required)
DNA SMART™ ChIP-Seq Kit (SMART)	Takara Bio USA, Inc.	5-step procedure of denaturation, dephosphorylation, T-tailing, DNA replication and template switching by reverse transcriptase and PCR. Compatible also with ssDNA. 1 purification step.	0.1 – 10 ng	Illumina
TELP	Xu lab [38]	5-step procedure of end-repair, poly-C-tailing, biotinylated primer extension, exonuclease digestion & streptavidin purification, adapter ligation and PCR. Compatible also with ssDNA. 3 purification steps.	0.025–25 ng	Illumina
ThruPLEX®	Rubicon Genomics	3 stage process of end repair, stem-loop adapter ligation and PCR amplification. 1 purification step.	0.05–50 ng	Illumina