of this window. In the export window, select “CSV Data
(Text) (∗.txt)” under the “Save as type” options. Next, specify a name and location for the exported data file, and click the
“Save” button.
105. For example, in the Vision Research Phantom Camera Control application, the timestamps for each frame (“Elapsed
Time from Trigger”) are displayed in microseconds. Thus,
multiply by 10
À6 s/μs to convert to seconds. Do not perform
any rounding on the resulting value, to prevent loss of
precision.
106. Save the resulting value to a precision commensurate with the
video frame rate and temperature rate of change. For the
analysis of kinetics, it will be necessary to distinguish between
interpolated temperature values corresponding to events in
successive video frames. Thus, the minimum numerical precision should equal the magnitude of the temperature interval
T k + 1 – T k , divided by the number of video frames acquired in
the time interval t k + 1 – t k . For example, if the cooling rate was
150
C/min and the image acquisition rate was 2500 fps,
then the required precision in the interpolated temperature
calculation is at least three decimal places (0.001
C).
107. This represents a simplified approach to analysis of censored
data. Alternative approaches exist that do not require data
points to be discarded, but such techniques are beyond the
scope of this chapter. Nonetheless, if consistency is maintained in the experimental procedures (i.e., if the start and
end temperatures of each video recording are consistent
among replicate trials), then the risk of having to discard
intracellular freezing events from analysis will be low.
108. It is important to note that one should not exclude from this
total any cells in which no intracellular ice formation was
detected (unless the cell was already omitted from analysis
on the basis of criteria given in step 1 in Subheading 3.9).
109. One possible scenario that would yield the data shown in
Table 2 is the following hypothetical case. In this example, it
is assumed that there were two replicate experiments with
three cells in each video, all of which underwent intracellular
freezing and were never obscured from view. In one video, the
recording start and end times corresponded to interpolated
temperatures of À1.000 and À21.000
C, respectively; the
corresponding intracellular ice formation events had interpolated temperature values of À3.890, À11.123, and
À13.768
C. In the other video recording in this example,
the start and end temperatures were À4.000 and
À24.000
C, whereas the intracellular ice formation events
occurred at À7.250, À11.124, and À22.446
C. Thus, the
High-Speed Video Cryomicroscopy
267
(Text) (∗.txt)” under the “Save as type” options. Next, specify a name and location for the exported data file, and click the
“Save” button.
105. For example, in the Vision Research Phantom Camera Control application, the timestamps for each frame (“Elapsed
Time from Trigger”) are displayed in microseconds. Thus,
multiply by 10
À6 s/μs to convert to seconds. Do not perform
any rounding on the resulting value, to prevent loss of
precision.
106. Save the resulting value to a precision commensurate with the
video frame rate and temperature rate of change. For the
analysis of kinetics, it will be necessary to distinguish between
interpolated temperature values corresponding to events in
successive video frames. Thus, the minimum numerical precision should equal the magnitude of the temperature interval
T k + 1 – T k , divided by the number of video frames acquired in
the time interval t k + 1 – t k . For example, if the cooling rate was
150
C/min and the image acquisition rate was 2500 fps,
then the required precision in the interpolated temperature
calculation is at least three decimal places (0.001
C).
107. This represents a simplified approach to analysis of censored
data. Alternative approaches exist that do not require data
points to be discarded, but such techniques are beyond the
scope of this chapter. Nonetheless, if consistency is maintained in the experimental procedures (i.e., if the start and
end temperatures of each video recording are consistent
among replicate trials), then the risk of having to discard
intracellular freezing events from analysis will be low.
108. It is important to note that one should not exclude from this
total any cells in which no intracellular ice formation was
detected (unless the cell was already omitted from analysis
on the basis of criteria given in step 1 in Subheading 3.9).
109. One possible scenario that would yield the data shown in
Table 2 is the following hypothetical case. In this example, it
is assumed that there were two replicate experiments with
three cells in each video, all of which underwent intracellular
freezing and were never obscured from view. In one video, the
recording start and end times corresponded to interpolated
temperatures of À1.000 and À21.000
C, respectively; the
corresponding intracellular ice formation events had interpolated temperature values of À3.890, À11.123, and
À13.768
C. In the other video recording in this example,
the start and end temperatures were À4.000 and
À24.000
C, whereas the intracellular ice formation events
occurred at À7.250, À11.124, and À22.446
C. Thus, the
High-Speed Video Cryomicroscopy
267