DNA immobilized on particles is becoming increasingly important for biotechnological applications such as production of hybridization kits, gene therapy with DNA delivery to cells, infection diagnostics; detection of microbial resistance to antibiotics in clinical samples and production of DNA chips among many others. Here immobilization of lambda-bacteriophage DNA onto polystyrene microspheres covered with a dioctadecyldimethylammonium bromide (DODAB) bilayer is characterized by means of dynamic light scattering and zeta-potential analysis. DODAB bilayer fragments were obtained by sonication with macrotip, sulfate polystyrene (PSS) microspheres with 301 nm mean diameter were purchased from Interfacial Dynamics Corporation (Portland, OR) and l-DNA was from Sigma. At room temperature, PSS microspheres (2.5x10⁹ particles/mL) and DODAB bilayer fragments (0.03 mM) interacted for 1 h at  25^oC. Thereafter, l-DNA was added over a range of concentrations (1-20 microgram/mL) and mean zeta-average diameter (Dz) or zeta-potentials were determined as a function of DNA concentration. From 0-4 microgram/mL DNA, the particles were still positively charged and stable with sizes remaining close to 300 nm. Around 5 microgram/mL DNA, particles show zeta-potentials close to zero and they aggregate. At and above 6 microgram/mL DNA, there is charge reversal and the particulate becomes negatively charged but stable with reduced mean diameters (320-360 nm). Over the 6-9 microgram/mL DNA, the system was remarkably homodisperse resembling the low polydispersity of latex samples. The novel system will possibly find many uses in strategical applications.