Since the first DNA model was created approximately 50 years ago using molecular models, students and teachers have been building simplified DNA models from various practical materials. A 3D double-helical DNA model, made by placing beads on a wire and stringing beads through holes in plastic canvas, is described. Suggestions are given to enhance the basic helical frame to show the shapes and sizes of the nitrogenous base rings, 3' and 5' chain termini, and base pair hydrogen bonding. Students can incorporate random or real gene sequence data into their models. One example of a gene sequence, for the protein oxytocin, is given. Left-handed Z-DNA, as well as right-handed A-DNA and B-DNA models can be constructed. Aimed for use in high school science classes, it takes 2-3 hours to complete DNA models with 30 labeled base pairs. Photos of oxytocin models are included. The size of this sturdy model is appropriate for visually-impaired students to feel the helical shape and read the genetic code in Braille. This model is inexpensive so each student can make his or her own model. Model building reinforces the student's understanding of how the components of DNA--the sugar, phosphate, and N-base rings--are positioned three dimensionally to form a double helix.