Issue: April 2004
Research in Action
Advanced microscope displays its capabilities
La Trobe University's state-of-the-art confocal microscope commissioned in October 2002 is proving its tremendous worth in biochemical research, according to Dr Leann Tilley.
The $400,000 device was purchased from a grant obtained from the United Kingdom's Wellcome Foundation and awarded to Department of Biochemistry researchers, Dr Tilley, Professor Claude Bernard, Professor Nick Hoogenraad and Dr Mike Ryan.
A Reader in Biochemistry, Dr Tilley says the confocal microscope was proving invaluable in examining the organisation and dynamics of cells.
Scientists across the University - and in particular the Department of Biochemistry - employ the facility and many researchers are beginning to use it as an indispensable instrument for their doctoral thesis research.
Three PhD students have made excellent use of the Facility:
- Ms Olga Koutsopoulos, supervised by Dr Ryan, is investigating mitochondrial distri-bution within mammalian cells. She is using the confocal microscope to investigate 'Milton'—a human protein involved in moving mitochondria inside cells.
Mitochondria - small compartments in cells which supply energy in the form of a molecule called ATP - move along microtubule 'tracks' to provide ATP to different parts of the cells. 'We know Milton helps move mitochondria along these tracks but we are unaware how,' Ms Koutsopoulos says.
'I have appended a green fluorescent protein to Milton, expressed it in tissue culture cells, and then used the capacity of the confocal microscope with its increased resolution to determine where Milton is found in the cell and what happens to mitochondria when different levels of Milton are present.
'While this is pure research, there are potential applications since some mutations of Milton cause blindness in Drosophila flies - and this may eventually provide some clue to some forms of mammalian blindness.'
- Ms Sarah Frankland is also examining how proteins are trafficked around cells as part of research conducted in Dr Tilley's laboratory. Her efforts are aimed at finding a way to block malaria parasites from displaying virulence factors on the surface of infected red blood cells, thus enabling the infected cells to be destroyed by the immune system.
'I want to find how the protein of cerebral malaria arrives at its final destination on the surface of an infected blood cell. We use the confocal microscope to find out where it is under various conditions with a view to discovering a way to block the processes by which the protein is trafficked within red blood cells.
'The confocal microscope resolution is significantly better than other microscopes. Using a technique called fluorescence photobleaching we can look at protein dynamics and using dual labelling we can look at two or three fluorescence colours at the same time.'
- Ms Dong Wei Wang, supervised by Professor Bernard, is investigating potential treatments of multiple sclerosis (MS), a disease of the central nervous system.
'I am using the confocal microscope to examine damage to axons - the 'feet' of nerve cells. If axons are damaged, the nerves cannot control movement of the muscles. The confocal microscope enables us to examine optical sections of the axon. It allows us to build up three-dimensional images of nerve damage.
'The nerve cell axon is surrounded by a protein 'coat' - myelin - that protects the cells. This coat is thought as the first target to be damaged in MS. We want to know if both the axon itself as well as the myelin coat become damaged at an early stage of Experimental Autoimmune Encepha-litis, a disease model of MS. If so, drugs could be developed to protect the axon. Our animal model combined with confocal microscopy help us to investigate potential treatments of MS.'
Dr Tilley said that the introduction of the green fluorescent protein as a convenient and highly specific label of particular cellular components greatly assisted the students' research. As a result, molecular biology and cell biology have come together to allow major advances in the way the researchers look at cellular functions.
'The confocal microscope enables us to make molecular 'movies' of live cells in real time and can give researchers new perspectives on events inside the cell. For example it is possible to obtain information about the location and behaviour of molecules in live biological specimens.'•
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