• Question: How do you diagnose diseases with a laser?

    Asked by Jack D. ? to Micki, Aisling on 7 Nov 2015. This question was also asked by Diamo44, 628nand22, 388nand36, 574nand36, Maxim G.
    • Photo: Micki Mitchell

      Micki Mitchell answered on 7 Nov 2015:

      OK, I use a mechanism called “surface plasmon resonance” (SPR). This occurs on the surface of metals. I have a glass prism coated with a layer of gold. I shine light at an angle through the prism at the gold. The light bounces of the gold and hits a camera. This will give me a spectrum. Now I couple an antibody to the surface of the gold. I shine light through the prism again. The extra layer of antibodies causes the angle of light that bounces back to the camera to change slightly. I get a shift in the spectrum. Now I assay serum. If the disease is present, the antigen specific to the antibody will bind and add an extra layer, resulting in another shift of the spectrum. If the disease is not present, I won’t get the shift in the spectrum and I know you’re OK. 🙂

    • Photo: Aisling Kerr

      Aisling Kerr answered on 11 Nov 2015:

      It is not really my area but I did read a very interesting article recently about a group in Australia who made a laser that emitted light that certain gases could absorb. As there are certain diseases that affect the gases in your breath, for example kidney disease, you could use this laser to detect these gases and diagnose a disease!

Comments

  • Photo: Claire

    Claire commented on :

    I use laser light to detect diseases a little differently from Micki.
    Firstly I take a sample of blood that contains lots of healthy blood cells and possibly some cancer cells (hopefully not!). I put some nanoparticles, that have fluorescent molecules stuck inside them, in with the cells and these will only attach to cancer cells. Then I place the sample on a glass slide and look through a microscope to see the cells. In the microscope there is a laser light which when shone on cancer cells makes them ‘glow’ because of the fluorescent nanoparticles stuck to them. If I see some cells that are glowing through the microscope it unfortunately means that you may have a certain type of cancer and if not then you’re fine!

  • Photo: 494nand32

    494nand32 commented on :

    thank you for ancering my questions I found that information helpful 🙂