A read is a short sequence of DNA that has been taken directly from an organism’s genome. The procedure of Whole Genome Shotgun Assembly involves collecting large libraries of reads and piecing them together to re-create a complete genome. Reads applied to Whole Genome Shotgun Assembly are called shotgun reads.

Reads are created by laboratory sequencing methods such as Sanger sequencing; the method used affects the read’s length in bases, as well as its quality scores. For more information, see Sequencing.