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Applicability of thin film phase plates in biological electron microscopy

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ABSTRACT

Presented is an evaluation of phase contrast techniques in transmission electron microscopy. The traditional defocus phase contrast is compared to two recently developed phase plate techniques. One is the Zernike phase contrast transmission electron microscope, the other is the Hilbert differential contrast thransmission electron microscope. The imaging characteristics of each technique are discussed. Phase plate techniques provide improved contrast for ice-embedded biological samples which are a challenge for the conventional defocus phase contrast. The flat spectral response of the Zernike and Hilbert modes extends towards the low frequencies which are severely suppressed in the conventional defocus mode. Target applications for each of the phase contrast techniques are discussed based on the specifics of image formation and spectral transfer.

No MeSH data available.


Application ranges of various phase contrast techniques in TEM. CTEM = conventional TEM; ZPC-TEM = Zernike phase contrast TEM; HDC-TEM = Hilbert differential contrast TEM.
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f8-2_35: Application ranges of various phase contrast techniques in TEM. CTEM = conventional TEM; ZPC-TEM = Zernike phase contrast TEM; HDC-TEM = Hilbert differential contrast TEM.

Mentions: Fig. 8 shows the approximate application ranges of the discussed imaging modes. The conventional TEM (CTEM) has no loss of imaging electrons thus it has a signal-to-noise advantage in the high-frequency region. The resolution of biological sample observations is limited by the preparation technique and/or the electron dose. So for the same electron dose CTEM will produce images with higher resolution. However observation of larger objects in vitreous ice, where the low frequencies are important, can be a challenge for CTEM9,11. In such cases phase plate techniques produce better images.


Applicability of thin film phase plates in biological electron microscopy
Application ranges of various phase contrast techniques in TEM. CTEM = conventional TEM; ZPC-TEM = Zernike phase contrast TEM; HDC-TEM = Hilbert differential contrast TEM.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC5036645&req=5

f8-2_35: Application ranges of various phase contrast techniques in TEM. CTEM = conventional TEM; ZPC-TEM = Zernike phase contrast TEM; HDC-TEM = Hilbert differential contrast TEM.
Mentions: Fig. 8 shows the approximate application ranges of the discussed imaging modes. The conventional TEM (CTEM) has no loss of imaging electrons thus it has a signal-to-noise advantage in the high-frequency region. The resolution of biological sample observations is limited by the preparation technique and/or the electron dose. So for the same electron dose CTEM will produce images with higher resolution. However observation of larger objects in vitreous ice, where the low frequencies are important, can be a challenge for CTEM9,11. In such cases phase plate techniques produce better images.

View Article: PubMed Central - PubMed

ABSTRACT

Presented is an evaluation of phase contrast techniques in transmission electron microscopy. The traditional defocus phase contrast is compared to two recently developed phase plate techniques. One is the Zernike phase contrast transmission electron microscope, the other is the Hilbert differential contrast thransmission electron microscope. The imaging characteristics of each technique are discussed. Phase plate techniques provide improved contrast for ice-embedded biological samples which are a challenge for the conventional defocus phase contrast. The flat spectral response of the Zernike and Hilbert modes extends towards the low frequencies which are severely suppressed in the conventional defocus mode. Target applications for each of the phase contrast techniques are discussed based on the specifics of image formation and spectral transfer.

No MeSH data available.