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Michael Marko

  • Headshot portrait of Mike Marko next to a microscope.

    Michael Marko

    • Cellular and Molecular Basis of Diseases - Manager of the 3D-EM Facility
    • Adjunct Professor, College of Nanoscale Science and Engineering, SUNY Poly

    michael.marko@health.ny.gov


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Research Interests

As one of the founding members of our electron microscopy development lab, I have been working on advancing biological transmission electron microscopy (TEM) technology since 1976, and have been involved in several US or worldwide “firsts”. Examples are: stereoscopic 3-D image analysis; cryo-TEM tomography of native frozen tissue; use of cryo ion-milling to prepare frozen tissue and cells for cryo-TEM; phase-plate imaging for cryo-TEM.

I currently lead two NIH-funded research projects: (1) use of cryo-focused-ion-beam (FIB) milling to prepare vitreously frozen specimens for high-resolution cryo-TEM, and (2) use of phase-plate imaging to improve contrast of vitreously frozen specimens in the cryo-TEM. These are represented in the image to the left. (A) Scanning electron microscope (SEM) image of the surface of a block of native (frozen, unstained) muscle in which cryo-FIB milling was used to thin rectangular strips for cryo-TEM imaging. (B) cryo-TEM image from a thinned area in A. This is an example of the first cryo-TEM images recorded of native, frozen muscle; however it was recorded with a conventional high-defocus method. Such a method enhances contrast but results in complete loss of certain information. (C) TEM image of a frozen liver slice recorded in-focus, which in principle does not result in complete information loss, but the image has insufficient contrast for analysis. (D) TEM image of the same specimen recorded in-focus, but using a phase plate to enhance contrast without loss of information.

I am also manager of Wadsworth Center’s 3D-EM Facility, which includes several high-end electron microscopes, including a FIB-SEM (both FIB and SEM instruments combined in a single platform) and a new custom-made 300-kV phase-plate cryo-TEM. The Facility is available for use by both Wadsworth and external investigators.

Select Publications

Hsieh C, Schmelzer T, Kishchenko G, Wagenknecht T, Marko M.
Practical workflow for cryo focused-ion-beam milling of tissues and cells for cryo-TEM tomography.
J Struct Biol.
(2014)
185
(1):
32-41.
Kishchenko G, Danev D, Fisher R, He J, Hsieh C, Marko M, Sui H.
Effect of fringe-artifact correction on sub-tomogram averaging from Zernike phase-plate cryo-TEM.
Journal of Structural Biology.
(2015)
191
(3):
299-305.
Marko M, Meng X, Hsieh C, Roussie J, Striemer C.
Methods for testing Zernike phase plates and a report on silicon-based phase plates with reduced charging and improved ageing characteristics.
J Struct Biol.
(2013)
184
(2):
237-244.
Marko M, Leith A, Hsieh C, Danev R.
Retrofit implementation of Zernike phase plate imaging for cryo-TEM.
Journal of Structural Biology.
(2011)
174
(2):
400-12.
Marko M, Hsieh C, Schalek R, Frank J, Mannella C.
Focused-ion-beam thinning of frozen-hydrated biological specimens for cryo-electron microscopy.
Nat Methods.
(2007)
4
(3):
215-217.
Marko M, Hsieh C, Moberlychan W, Mannella CA, Frank J.
Focused ion beam milling of vitreous water: prospects for an alternative to cryo-ultramicrotomy of frozen-hydrated biological samples.
J Microsc.
(2006)
222
(Pt 1):
42-47.