How construct a LED Array?

The following information contains the steps that was done by the Unam Genomics Team of the iGEM 2010 in order to construct an improvised light dispositive to irradiate bioluminiscent cells.

Blue Led Array

Introduction

Synthetic Biology has been enabling changes in all bio-domains, one such being communication. Cellular communication has relied since time immemorial on chemical messengers to exchange information.

In the project of Unam Genomics Team at the iGEM 2010, their goal is to render the chemical barrier deprecated by using a non-chemical messenger: photons. These will transport information between cells that have been designed to sense and emit light, thus creating a photon-based inter-cellular communication system.

They decided to break down their devices into 3 sub-devices: Reception, Emission, and Transmission. One of the most important things in the project is how the cell receive the information and process it. The intensity of the answer is proportional to the level of the message, so is necessary to characterize the black magic box that occurs in the cell.

A simple aproach to reach this goal is know how many photons are needed to turn on the system and to find the level of the expression in the cell. We then, constructed a plate with variable light which have autonomus temporizer.

In order to allow you to test our receptors or, if you have a lot of free time in the lab, do the experiments; we report a do it yourself.

Requeriments

A LED is a a semiconductor light source used as indicator lamps in many devices, and are increasingly used for lighting. Small size, an incredibly emission, a good life time and do not increase significantly the temperature of the irradiaded object... They are perfect to the biology!!!.

Another good thing of the LEDs is the diversity of sizes, the 5mm fit perfectly to an ELISA black plate used to measure fluorescence, so you can use 2 plates one for the array the LED and the other with the fluorescent strains.

You may remember in that far away class of electricity that the light in a circuit pass trough all the devices and these generate resistance to the flux to electrons. By the law of Ohm, we need an efflux of electrons that can go trough all the LEDs without problems, so we require an energy transformer with high amperage to maintain all the LEDS with the same intensity.

Also you maybe want use a triplay perfored board to do the things more easier and a box and black paint to reduce the external noise caused the sun rays which cointain all the spectrum visible.

So:

What do you need

• Soldering kits
• 96 LEDs 5mm 3 volts of the color that you want
• Switches to turn off-on each pair of LEDS
• ELISA 96-well black plate
• Duct tape
• Pincers
• Triplay perfored board, 12X8 holes.
• 4 meters of copper wire
• An energy transformer (120 V ~ 3V) of at least 2 ampers.
• Patience :)

Step by step

Early stages

You might know how will be the circuit, the next diagram explain all the electric network:

Diagram of the electric network

Steps:

1

You need cut aprox. 40 cm of clean wire to create a "serpent" that will cross between two rows of holes in the ELISA plate. Stick the sides with duct tape to better maneuvering.

2

You can start arranging the LEDs in the position that have assigned in the diagram. They were connected by pairs in parallel to the circuit to nivelate all the chargeUser:Hector_Medina/Notebook/iGEM_2010_Personal_Log/2010/06/25. Remember that the longest term of the LED is the positive one.

3

Use the pincers to form loops in the negative legs of the LEDs, maybe 2 mm of diameter, the loop will hold the copper wire which will be conected to the copper "serpent" in the ELISA plate. Cut copper wires of two centimeters and clean both terms, one 5 mm up, to connect to the plate and the other 1 cm, to pass trough the loop of the LEDs.

4

Create loops again, but now in the positive legs of the LEDs. Cut copper wires of five centimeters (or the long necessary to fit in a box) and clean both terms, one 5 mm up, to connect to the positive wire that is going to be in the up of the box, and the other 1 cm, to pass trough the loop of the LEDs.

5

In this momment you will able to test all the conections with a charge of 3 volts and taking care of the positive and negative poles. Connect ONLY ONE term of the serpent copper to the cell´s negative pole, and the positive to one wire that connect a pair of LEDs. If all is correct you will proced to weld all the conections.

6

Now you need pass trough your perfored board all the positive wires. To perform this we recommend you pass one by one sticking at the board with duct tape. Next you need a positive serpent at the up of the board which conect all you wires, just do the same before, but now pass the serpent trough the last holes.

7

Cut copper wires as long as the centimeters which passes the positive wires trough your perfored board. Conect the switches. Test your switches. Weld your switches.

8

In the finish, you will want protect all your hard work, you can put all the circuit in a box and use duct tape anywhere to stick the things.

Now just test the system, conect the down serpent to the negative pole and the up serpent to the positive pole, turn off-on all your LEDs.

For any question see the images. Also, you can email us:

• [| Amhed M. Vargas Velazquez]
• [| Hector Medina]

More information:

• Bitacore of our team experience From 22/06 to 27/06
• The experiment and Technical issues
• Unam Genomics iGEM 2010 Wiki