TY - JOUR
T1 - Contrast transfer for frozen-hydrated specimens II. Amplitude contrast at very low frequencies
AU - Toyoshima, Chikashi
AU - Yonekura, Koji
AU - Sasabe, Hiroyuki
N1 - Funding Information:
We thank David Stokes, now at the University of Virginia, for taking a set of images of Ca-ATPase. We also thank Nigel Unwin for discussions. This research was supported in part by a Grant-in-Aid from the Ministry of Education, Science and Culture of Japan.
PY - 1993/1
Y1 - 1993/1
N2 - The contrast transfer properties of frozen-hydrated specimens were examined quantitatively for low spatial frequencies (1/350-1/160 Å-1). Specimens used were tubular crystal of two membrane protiens, the acetylcholine receptor and calcium-ATPase. These specimens were found to behave as weak-phase-weak-amplitude objects. The contribution of amplitude contrast was 5.8% at 120 kV and 4.8% at 200 kV accelerating voltage. Combined with previous results, the level of amplitude contrast showed little dependence on the spatial frequency over the range examined so far (1/350-1/35 Å-1).
AB - The contrast transfer properties of frozen-hydrated specimens were examined quantitatively for low spatial frequencies (1/350-1/160 Å-1). Specimens used were tubular crystal of two membrane protiens, the acetylcholine receptor and calcium-ATPase. These specimens were found to behave as weak-phase-weak-amplitude objects. The contribution of amplitude contrast was 5.8% at 120 kV and 4.8% at 200 kV accelerating voltage. Combined with previous results, the level of amplitude contrast showed little dependence on the spatial frequency over the range examined so far (1/350-1/35 Å-1).
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U2 - 10.1016/0304-3991(93)90179-2
DO - 10.1016/0304-3991(93)90179-2
M3 - Article
AN - SCOPUS:0027405822
SN - 0304-3991
VL - 48
SP - 165
EP - 176
JO - Ultramicroscopy
JF - Ultramicroscopy
IS - 1-2
ER -