The Double Helix -Glass Bead DNA Model V2.0

Here is my second glass bead DNA double helix model. In this model I used wire instead of thread and I also added more space between the base pairs.

Here is a link to my first model.

Materials:

-Five different colours of seed beads (I used glass beads).

one colour makes up the sugar-phosphate backbone.
four colours for the bases, pair up the colours so that they always appear together. (eg red-blue, green-yellow).

- ~50cm strand of jewelry wire (should be more than you need, but rather have too much than too little).

-Scissors for cutting the wire.

The First Bead

The first bead will be the colour of the sugar-phosphate backbone.
Thread one end of the wire through the first bead, pull it through until it is in the middle of the thread. (see images below)
Take the other end of the wire and thread it through the bead in the opposite direction.
Pull ends tight.

The First Row

Thread four beads (the same colour as the first bead) through each of the two wire ends (these are end spacers.)
Pull these through to the first bead.
The first row consists of 6 beads, the outer two are the same as in the previous step, which will be the sugar-phosphate backbone (dark blue), the middle beads are the base pairs; two beads of each colour in this case two yellow and two green beads. (See my colour pattern in step 5)
Thread one end of the wire through the six beads, pull it through to you meet up with spacer beads. (see images below)
Take the other end of the wire and thread it through the beads in the opposite direction.
Pull ends tight.

The Second Row

Thread two beads (the colour of the sugar-phosphate backbone) through each of the two wire ends, these are the spacers between the base pairs.
Pull these through to the previous row.
The second row consists of 6 beads, the outer two are the same as the sugar-phosphate backbone (dark blue), the middle beads are the base pairs; two beads of each colour in this case two red and two light blue beads. (See my pattern in step 5)
Thread one end of the wire through the six beads, pull it through to meet up with the spacer beads. (see images below)
Take the other end of the wire and thread it through the beads in the opposite direction.
Pull ends tight.

Continuing On......

Continue adding more rows of beads using the pattern below, with two bead spacers between the base pairs for a total of 14 rows (14bp). You can make it longer if you would like.

The colour pattern is just a suggestion, feel free to play around with the colours, just make sure you keep your base pair colours together.

You can have fun with this by assigning the colours a specific nucleotide (eg. red=Guanine, blue=Cytosine, yellow=Adenine, green=Thymine). Make your favorite amino acids, use TTAGGG repeats and call it a telomere, or copy a gene sequence (although the average human gene is 3000bp this is probably not a good idea).

Finishing Up

Thread four beads (dark blue) through each of the two wire ends.
Pull these through to the previous row.
Thread one end of the wire through the last bead (again,dark blue), pull it through to meet up with spacer beads.
Take the other end of the wire and thread it through the bead in the opposite direction.
Take one of the wires and loop around and thread through the bead again, pull tight, this is to finish it off
Tie a knot close to the bead, then make a loop for hanging and tie another knot and cut off the excess wires.

Holding either end of the DNA, bend and twist to form a helix shape. (sorry I don't have pictures of this, both hands were busy bending and twisting).

The helix is similar to a corkscrew or two interlocking bedsprings, you may need to play around with the shape to get the look you want.