There have been many applications proposed for carbon nanotubes (CNTs). In spite of these applications they are not being used vastly for a few fundamental difficulties in utilizing them including not being soluble in aqueous and non-aqueous solutions. One method for dispersing and solubilizing them in aqueous solutions is attaching single stranded DNA to the outer wall of single walled carbon nanotubes. The effective parameter in the solubility (efficiency in gel filtration) is the strength of hydrogen bonds between CNTs and DNA in three solvents possessing strong hydrogen bonds: H2O, methanol (MeOH) and N,N'-dimethyl formamide (DMF). Electronic absorption spectra, Superdex TM 200 10/300 gel-filtration and scanning electronic microscopy (SEM) also support van der Waals wrapping of DNA on CNTs. It was found that DMF exhibit higher solubility than MeOH and H2O. (C) 2011 Elsevier B. V. All rights reserved.