When the bead is pressed onto the cover slip, the confinement leads to a clear fluorescence increase owing to the rigidochromic effect: a roughly circular fluorescent spot appears and increases in size as the force is increased.
Images of the fluorescent spot on the surface of sample 2 in the initial and bleached states are shown in the inset.
Rarely, more than one fluorescent spot was observed to simultaneously stop at the same location.
We are also grateful to Tarmo Äijö for implementing the fluorescent spot detection algorithm.
Most clinical screening tests measure the enzymatic formation of NADPH from NADP, such as the semiquantitative fluorescent spot test or the quantitative spectrophotometric test [19] [22].
Moreover, a bright fluorescent spot was observed in the nucleus in more than 60% of the cells (Figure 2A, left panel).
The average frequencies of cells showing a bright fluorescent spot were compared using Student's t-tests as indicated in the figure legends.
Custodio and coworkers showed that the frequency of cells showing a bright fluorescent spot is drastically reduced when transcription is inhibited [24].
DAPI staining was used to confirm that each fluorescent spot counted was indeed a nucleus, as partial nuclei were often encountered in the sections.
Since the images were stored on a server, different algorithms could be applied at different times to extract various quantitative measures, such as fluorescent spot count, spot area or spot intensity per animal.
However, more than 40% of the cells displayed a bright fluorescent spot in the nucleus, similar to the one observed in cells that expressed the wt gene (Figure 2A, right panel).
