title: sRNAs Phaeodactylum tricornutum
design: total RNA was extracted from diatom cells using the Trizol method (Invitrogen, USA). sRNAs were separated by size fractionation on denaturing polyacrylamide gels and then fragments in the 18–35 nt size range were purified. The RNA samples were sent for cDNA synthesis and Illumina sequencing to Vertis Biotechnologie AG company (www.vertis-biotech.com). The purified RNAs were poly(A)-tailed and ligated using a RNA adapter to the 5´-phosphate of the small RNAs. First-strand cDNA synthesis was performed using an oligo(dT)-adapter primer and M-MLV RT (Ambion), then followed by PCR amplification.  The five growth conditions tested are Normal Light (SRR1509887), Low Light (SRR1509888), Dark (SRR1509889), High Light (SRR1509890) and Iron Starvation (SRR1509891). After downloading, please verify that the read count information is in agreement with the information provided in the article.