Recently, we proposed a 3-D graphical representation of DNA sequences [Chem. Phys. Lett. 379 (2003) 412]. Based on this representation, we Outline one such approach by constructing a 15-component vector whose components are the average bandwidth of the DID matrices. The examination of similarities/dissimilarities among the coding sequences of the first exon of beta-globin gene of different species illustrates the utility of the approach. (C) 2004 Elsevier B.V. All rights reserved.