using single-stranded phage m13 dna probes chemically labelled with one biotin per 100-400 residues and dot-blot hybridization reactions on nitrocellulose , as little as 0.5 pg ( 6 x 10 ( -18 ) mol ) of target dna was detected colorimetrically by avidin or streptavidin complexes with acid or alkaline phosphatase from three commercial sources .
C0012935
single-stranded
C0012854
dna