Material:

• Scissors;
• Ruler;
• String (optional – only if the nucleic acid is a straw and not a poster paper);
• Sewing needle or other similar object with average thickness;
• Yellow, blue, green and red contact paper (optional – only if the nucleic acid is a straw and the straw has only one color or other colors that are not yellow, green, blue and red);
• Metal stem, for example: wire, bicycle wheel rim, or umbrella stretcher;
• Adhesive tape;
• Wood base, or other material;
• A small perforated base for virus maintenance over the wood base (Styrofoam, cork, rubber, etc.);
• Thin poster paper (optional – only if the nucleic acid is not a straw);
• Drinking straws: They can be straight or articulated. For straight straws and nucleic acid not made of poster paper, 44 straws must be used:
  • 30 of the same color to form 20 equilateral triangles;
  • 3 of the same color, but a different color from that used for the 30 straws to form glycoproteins;
  • 4 yellow, blue, green and red to organise the dinucleotides or 4 of any color to be covered with yellow, blue, green and red contact paper;
  • 7 straws, preferably of the same color used for the 30 straws, to be cut and to form, together with the side surplus, the remaining fittings. 7 straws, preferably of the same color used for the 30 straws, to be cut and to form, together with the side surplus, the remaining fittings.

In case the straws are articulated and the nucleic acid is not made of poster paper, 64 straws must be used, 60 of the same color to form 20 equilateral triangles and 4 straws in yellow, blue, green and red color to form dinucleotides, or 4 straws of any color to be covered with contact paper of your favourite colors.

Procedures:

1) Assembly of 20 equilateral triangles:

In order to assemble the triangles, you must check if the straws are straight or articulated. If they are articulated ones, vertices will be formed by straw articulation (Figure 1 and 2).

2) Assembly of 20 equilateral triangles:

• 2.1) Straight Straws:
• Out of 44 straws, cut 30 straws of the same color in 10 cm-pieces (60 pieces) and keep the surplus to use later for side or vertex fittings of the 20 triangles. Use 7 additional straws, preferably of the same color as the other 30 straws, to be cut and to form fittings or remaining vertices (figures 3, 4 and 5);
• Use the 10cm-pieces of straw, in groups of 3, to form the sides of the triangles, and use the surplus, in groups of three, from the 30 and 7 straws that were cut to assemble fittings or side vertices (figure 6);
• The use of these pieces to form vertices or fittings must follow the instruction below (figure 7, 8 and 9);
• Fold them vertically (longitudinally);
• Fold them on half horizontally (transversally);
• Insert them, until half the way, through the holes in each side that form the vertex;
• Reinforce these vertices with adhesive tape (figure 10).

• 2.2)Articulated Straws:
• Out of 64 straws, cut 40 straws of the same color in a way the long straight parts measure 9 cm and the short straight parts measure 4.5 cm (figure 3, 4, 5, 6 and 7);
• Cut 20 straws in a way each side of the articulation measures 3 cm of straight parts and keep the surplus to use later in dinucleotides; (figures 10 and 11);
• All vertices are articulated;
• Use the 20 pieces cut by half and the articulations of 20 straws to close the triangle, forming one of the sides (4.5 cm + 4.5 cm) and vertices, as follows (figure 12): crush the ends of the cut pieces and insert them on both 4.5 cm parts to bind them together; bind the two loose ends of this set by inserting the straight parts of each side of the articulation (taken from 20 straws), forming the vertex which is opposite to the basis of the equilateral triangle (figure 15 and 16).

3) Assembly of Adenovirus Nucleic Acid (DNA):

• Assembly of Adenovirus Nucleic Acid (DNA) Made of Poster Paper:

  • Cut to form a seamless 0.5cm wide strip in the entire poster paper;
  • This cut must be seamless throughout the entire extension of the poster paper until two free ends are obtained;
  • The number of poster paper strips must be sufficient to occupy the capsid volume in the end.
• Assembly of Adenovirus Nucleic Acid (DNA) with Same Color Straight Straws (figure A, B, C, D, E):
  • Cut some of the surplus of the straw to obtain 10 pieces of 6 cm long each;
  • To form dinucleotides, cover with contact paper every 3 cm of the same straw piece, with different colors: green with red and yellow with blue. Therefore, in the end, you will have 5 yellow/blue dinucleotides and 5 green/red dinucleotides;
  • With a needle, or other puncturing device with average thickness, puncture each dinucleotide in the junction of the colors (in the middle of the straw piece);
  • Cut 10 pieces of straw measuring 0.5cm long to serve as spacers between dinucleotides;
  • Insert a long piece of string through the ends of the first dinucleotide, leaving two longs ends of string to be inserted in all other dinucleotides one after another;
  • o Give a double helix shape to the DNA, by giving it a complete swing, and tie both ends of the string in the stem.
• Yellow, blue, green and red straight straws (figures a, b):
  • Cut some of the surplus of the straw to obtain 5 pieces of each straw, where yellow and green straws measure 4 cm long, and blue and red straws measure 3 cm long;
  • To form dinucleotides, insert 1cm of the larger pieces into the smaller pieces in a way the set has 6cm long: Insert the green straw into the red straw and the yellow one into the blue one. Therefore, in the end, you will have 5 yellow/blue dinucleotides and 5 green/red dinucleotides;
  • With a needle, or other puncturing device with average thickness, puncture each dinucleotide in the junction of the colors;
  • Cut 10 pieces of straw measuring 0.5cm long to serve as spacers between dinucleotides;
  • Following a random order in dinucleotide color pairs, insert each one of them through the hole made with the needle in the metal base, and place a spacer between them;
  • Insert a long piece of string through the ends of the first dinucleotide, leaving two longs ends of string to be inserted in all other dinucleotides one after another;
  • o Give a double helix shape to the DNA, by giving it a complete swing, and tie both ends of the string in the stem.

4) Assembly of the Nucleocapsid

• 4.1) Straight straws.
• In 5 bases with no intermediate piece, glue 5 triangle bases in one of the arrays to form the bottom piece of the capsid (figure 16);
• Make a hole in the centre of the wood base to insert the stem of the nucleic acid;
• Place a perforated cork over the wood base hole, lean the set of bottom and intermediate pieces over the cork and insert the stem of the nucleic acid (figure 17);
• Glue the other array in the intermediate part, base to base, to form the top piece (figure 18);
• Place 4cm straw pieces in vertices to form glycoproteins (figure 19).

• 4.2)Articulated Straws.
• In 5 bases with no intermediate piece, glue 5 triangle bases in one of the arrays to form the bottom piece (figure 20);
• Make a hole in the centre of the wood base to insert the stem of the nucleic acid;
• Place a perforated cork over the wood base hole, lean the set of bottom and intermediate pieces over the cork and insert the stem of the nucleic acid;
• Glue the other array in the intermediate part, base to base, to form the top piece;
• Place corks in vertices to form glycoproteins.

Conclusions:

The schematic aspect of adenovirus is icosahedron, with the following characteristics: 20 triangle faces, 12 vertices and 30 edges;

Using straws to form the virus avoids wasting this material in the environment.