Cell News 01/2017
19
New Platforms for Automated Live Imaging -
Particular Strengths and Possibilities
Dr. Sören Alsheimer, Sales 3D Imaging Systems, Carl Zeiss Microscopy GmbH
SESSION 1: CELL BIOLOGY BY NUMBERS
Presenting author: Sören Alsheimer
ZEISS Celldiscoverer 7 is a brand new highend imaging plat-
form for automated live cell imaging. At the core of Celldiscov-
erer 7 an entirely new optomechanical concept, market-lead-
ing incubation solution and advanced automation features
work together to deliver the benchmark performance you
expect from ZEISS. In this talk we will highlight new technolo-
gies enabling highly efficient automated workflows that drive
your productivity, reduce user bias and enable new discoveries.
Selected application examples including single-shot whole well
imaging, whole embryo imaging and automated live cell imag-
ing will feature particular challenges and modern solutions.
A quantitative approach towards
understanding spindle shape
Abin Biswas, Gheorghe Cojoc, Jochen Guck and Simone Reber
Presenting author: Abin Biswas
IRI for the Life Sciences, Humboldt Universität zu Berlin
The metaphase spindle is a dynamic, self-organising molecular
machine that performs the critical function of segregating the
genome during cell division. In recent years, significant prog-
ress has been made in uncovering the fundamental molecular
components of the spindle. However, it is still unclear how
these components work together to give rise to the unique
spindle-like appearance. A force balance mechanism has been
suggested to be responsible for maintaining the spindle’s shape
and integrity. Forces are generated within the spindle due to
the action of molecular components such as motor proteins
and microtubule dynamics; as well as due to intrinsic physical
properties like elasticity and surface tension. This project aims
at quantifying the effect of these force generating components
and at understanding how they work together to give rise to
the bipolar spindle shape.
To achieve this, spindles were reconstituted in vitro in meta-
phase arrested Xenopus leavis egg extracts and their shape
was altered via biochemical and physical perturbations.
Biochemically perturbing the activity of Eg5 and Dynein
motor proteins using small molecule inhibitors and antibodies
drastically altered spindle morphology. However, the total MT
mass, spindle area and average density remained unaffected.
To physically perturb spindles and study its mechanics, an open
optical stretcher setup was developed. We have successful-
ly used the stretcher to exert force on and trap MT bundles,
centrosomes and spindles in Xenopus egg extract. This tool
will enable us to make contact free rheological measurements
and for the first time calculate parameters like surface tension.
Future experiments aim at deforming biochemically perturbed
spindles and comparing their micromechanics, to establish a
link between molecular and physical properties. Ultimately, this
experimental data will be fed into a coarse grained force-bal-
ance model which shall be applied to understand the property
of spindle shape globally.
