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CALSCALE:GREGORIAN
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BEGIN:VEVENT
DTSTAMP:20260307T024704Z
UID:https://www.mpsd.mpg.de/events/13446/17182
DTSTART:20180411T140000Z
DTEND:20180411T153000Z
CLASS:PUBLIC
CREATED:20180327T143008Z
DESCRIPTION: Transmission electron microscopy (TEM) has traditionally been 
 associated with the study of thin solid samples in vacuum. With the availa
 bility of reliable thin membranes of silicon nitride\, TEM of liquid speci
 mens has become accessible with nanoscale resolution in the past decade [1
 ]. The usage of scanning transmission electron microscopy (STEM) presents 
 a novel concept to study membrane proteins within whole mammalian cells in
  their native liquid environment [2]. The cells in liquid are placed in a 
 microfluidic chamber enclosing the sample in the vacuum of the electron mi
 croscope\, and are then imaged with STEM. It is not always necessary to en
 close the cells in the microfluidic chamber. For many studies\, it is suff
 icient to obtain information from the thin outer regions of the cells\, an
 d those can be imaged with high resolution using environmental scanning el
 ectron microscopy (ESEM) with STEM detector [3]. A third option is to cove
 r a liquid specimen under a thin membrane of graphene providing the thinne
 st possible layer [4]. Liquid STEM was used to explore the formation of HE
 R2 homodimers at the single-molecule level in intact SKBR3 breast cancer c
 ells in liquid state [3]. HER2 is a membrane protein and plays an importan
 t role in breast cancer aggressiveness and progression. Data analysis base
 d on calculating the pair correlation function from individual HER2 positi
 ons revealed remarkable differences its functional state between rare- and
  bulk cancer cells with relevance for studying the role of cancer cell het
 erogeneity in drug response. We discovered a small sub-populations of canc
 er cells with a different response to a prescription drug [5]. Liquid STEM
  was also used to explore the behavior of nanoparticles in liquid in time-
 lapse experiments. It was discovered that nanoparticle movement in close p
 roximity of the supporting silicon nitride membrane was three orders of ma
 gnitude slower than what was expected on the basis of Brownian motion for 
 a bulk liquid [6]\, pointing to the existence of a layer of highly ordered
  liquid at the membrane. References [1] de Jonge\, N. and Ross\, F.M. <i>N
 at. Nanotechnol.\, </i>6\, 695-704 (2011) [2] de Jonge\, N.\, et al. <i>Pr
 oc. Natl. Acad. Sci.\, </i>106\, 2159-2164 (2009) [3] Peckys\, D.B.\, et a
 l. <i>Sci. Adv.\, </i>1\, e1500165 (2015) [4] Dahmke\, I.N.\, et al. <i>AC
 S Nano\, </i>11\, 11108-11117 (2017) [5] Peckys\, D.B.\, et al. <i>Mol. Bi
 ol. Cell\, </i>28\, 3193-3202 (2017) [6] Verch\, A.\, et al. <i>Langmuir\,
  </i>31\, 6956–6964 (2015)\nSpeaker: Niels de Jonge
LAST-MODIFIED:20180405T142923Z
LOCATION:CFEL (Bldg. 99)\, Room: Seminar Room III\, EG.080
ORGANIZER;CN=R. J. Dwayne Miller:mailto:
SUMMARY:MPSD Seminar: Liquid-Phase Electron Microscopy of Cells and Nanomat
 erials in Liquid 
URL;VALUE=URI:https://www.mpsd.mpg.de/events/13446/17182
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