New Look on Science
A new era of science is upon us. Unlike before now when science relied on basic microscopy to illuminate cells that were previously too blurry to imagine what was actually going on inside. Now with the help of high-speed imagery, and fluorescent emissions microscopy, we can see exactly what is going on in the underpinnings of life by breaking the diffraction barrier.
Microscopes were first invented in 1590 by two eyeglass makers later to have the term, “Microscope” coined by Giovanni Faber coined the name microscope for Galileo Galilei‘s compound microscope in 1625. We now commonly use the modern light microscope that we’ve all probably played with at some point in our early schooling.
The issue with modern light microscopes is the fact that when looking at cells they are blurry. Further, more complex microscopes such as electron microscopes is the fact that there is a great deal of preparation in order to look at something. Generally something has to be suspended in formaldehyde, or plated in gold.
Now with the recent break through in microscopy we can see exactly what is going on in a cell. Previously, the diffusion barrier warped light around cells giving them a lensed effect just like when looking at a cluster galaxy with a black hole in front of it (lensing effect). The significance of this break through is the fact that we now know for certain which processes are happening when we are looking inside of a cell.
SIM (~100 nm)
Structured illumination microscopy shines a striped pattern of light onto a sample. That light interacts with light from fluorescent tags on cellular material and generates a pattern of interference called a moiré fringe. Using a series of moiré fringes it’s possible to mathematically extract and reconstruct a super-resolution image. SIM is ideal for looking at entire cells in 3-D, ensembles of cells or multiple cellular structures at once. View larger image SIM: Lothar Schermelleh, Univ. of OxfordSTED (~30–70 nm)
When a focused light beam hits a fluorescent-tagged specimen, it generates a blurry halo. With stimulated emission depletion microscopy, a second laser shines a doughnut-shaped beam of light that turns off the excited molecules in the halo. This provides a sharper view that, when scanned across the sample, produces a super-resolution image. View larger image
STED: R. Medda, D. Wildanger, L. Kastrup and S.W. Hell/Max Planck Institute
PALM (~10–55 nm)
Photoactivated localization microscopy incorporates into a sample special fluorescent proteins that can be toggled between on and off states when hit with a particular wavelength of light. This allows researchers to illuminate a subset of molecules in a sample and eliminate overlapping fluorescence that would blur details if everything in the sample was lit up at once. iPALM (interferometric PALM) provides images in 3-D. View larger image
PALM: J.A. Galbraith, G. Shtengel, H.F. Hess and C.G. Galbraith/NINDS/NIH, Janelia
STORM (~20–55 nm)
Stochastic optical reconstruction microscopy, developed around the same time as PALM, also relies on fluorescent tags that can be switched on and off. In STORM’s case, the tags can be dyes or proteins. Using dyes may require an extra step, but they can be switched on and off more quickly and don’t burn out as fast as fluorescent proteins. Dyes can also be attached to genetic material. View larger image
STORM: M. Bates et al/Science 2007
Indeed such inventions are so new that many scientists are certain there are many new discoveries to come. Who knows what sort of views these new techniques may yield with a few more tweaks, and inventions.
As mentioned before most science about cells is simply hypothesised about how they operate. Now we can look inside and see how exactly they are working with their co-habitants. Science is amazing.