Abstract In this numerically work, we investigate the electronic transport along model deoxyribonucleic acid molecules using an effective tight-binding approach that includes the backbone onsite energies. The transmission probability, localization length and participation number are examined as a function of system size, energy dependence, and the contact coupling between the leads and the deoxyribonucleic acid molecule. On one hand, the transition from an diffusive regime for short systems to a localized regime is identified, suggesting the necessity of a further length scale revealing the system borders sensibility. On the other hand, we show that the localization length and participation number, do not depended of system size and contact coupling in the thermodynamic limit. Finally we discuss possible length dependent origins for the large discrepancies among experimental results for the electronic transport in deoxyribonucleic acid sample.