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<div class="WordSection1">Reminder for today's seminar. Highly
topical subject area!<br>
<p class="MsoNormal"><b><span style="color:#1F497D"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><b><span style="color:#1F497D">2pm Friday
10<sup>th</sup> Oct JA3.27<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="color:#1F497D"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><b><span style="color:#1F497D">Robert Pal,
<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="color:#1F497D">University
of Durham.<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="color:#1F497D"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><b><span style="color:#1F497D">In the
pursuit of higher resolution in optical microscopy
</span></b><span style="color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Abstract :<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">The
optical probes and cellular stains commonly used in
microscopy are usually fluorescent organic molecules or
recombinant proteins which have been used in many areas of
cellular biology leading to an enhanced understanding of
cellular processes and molecular interactions. However, many
of these dyes have inherent drawbacks, such as issues
associated with their toxicity, photostability and
selectivity.
<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">Over
the past few years, emissive lanthanide complexes have been
shown to be alternative robust and bright cellular stains.
These probes not only stain selected cellular organelles in
a wide variety of cell lines, but also possess long
lifetimes allowing ‘autofluorescence free’ time-gated
detection to be achieved without perturbation of cellular
homeostasis.[1]
<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">Recent
years show the emergence of novel optical microscopy
techniques to surpass the optical diffraction barrier and
visualize the ‘living’ cell in higher resolution. Governed
by Abbe’s law, the highest achievable spatial resolution is
dictated by the wavelength of excitation light d ~
Lambda(exc.)/2. The invention of confocal microscopy paved
the way to the development of new optical (hardware) and
software based super-resolution methodologies, such as SIM
or STED. Since these techniques are limited by their
well-known experimental drawbacks,[2] it is possible to
improve lateral resolution using UV light as illumination
source (Kohler 1904) with bright non-disruptive molecular
probes.
<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">We
seek to develop Phase Modulation Nanoscopy (PhMoNa) a novel
super-resolution technique using spatially modulated
illumination intensity, capable of improving experimental
resolution in both lateral and axial domain by a factor of
2. The work initially uses functionalised Ln(III) complexes
as probes, synthesized in tandem to instrumental
development. The advantageous properties of the lanthanide
based probes have been further exploited in Durham in recent
years, allowing high resolution visualization (<130 nm at
355 nm excitation) of selected cellular organelles in long
term live cell experiments, whilst reporting on the
micro-chemical environment. Owing to their beneficial
photophysical, brightness and cellular accumulation
properties, UV exposure and photo-bleaching were
minimized.[3]
<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">The
instrumental development involves modification of an
existing confocal (LSCM) system integrating a custom
spatially (sinusoidal phase) modulated laser to achieve
superior resolution of cellular substructures with an 8 fold
reduced voxel size. Another important advantage to emphasize
is that this approach (PhMoNa) promises to be a facile LSCM
based experimental set-up that can be safely used for
live-cell imaging. It will be one of the few applicable
nanoscopy techniques employing a compact white laser sources
for excitation. This is of key importance as the application
of white laser sources promotes PhMoNa to be utilized with
any currently commercially available cellular stain at any
given excitation wavelength. Thus, we seek to develop an
attractive alternative instrumental technique to be used by
the broad imaging community.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">1
C.P. Montgomery, B.S. Murray, E.J. New, R. Pal and D.
Parker, Acc. Chem. Res., 2009, 42, 925<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">2
L. Schermelleh, R. Heintzmann and H. Leonhardt, J.Cell.
Biol., 2010, 190, 165
<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-family:"Arial","sans-serif"">3
J.W. Walton, A. Bourdolle, S.J. Butler, R. Pal and D.
Parker, Chem. Comm., 2013, 49, 1600</span><span
style="font-size:12.0pt;font-family:"Cambria","serif""><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span><br>
</p>
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