Biology Reference
In-Depth Information
1.06
1.06
H
1
R-mTq2
H
1
R-sYFP2
1.02
1.02
0.98
0.98
1.0
10
100
1000
1.0
10
100
1000
t
(ms)
t
(ms)
1.0030
cross-correlation
1.0015
1.0000
1.0
10
100
1000
t
(ms)
FIGURE 11.3
Typical auto- and cross-correlation curves for HeLa cells cotransfected with H
1
R-
mTurquoise2 and H
1
R-sYFP2. The curves were fitted (black lines) to models including terms
for diffusion, dark-state kinetics, and the presence of monomers and dimers.
cross-correlated using multi-tau algorithms (
Wahl, Gregor, Patting, & Enderlein,
2003
) resulting in the two autocorrelation curves
G
CC
(
t
) (for the CFP channel)
and
G
YY
(
t
) (for the YFP channel) and the cross-correlation curve
G
CY
(
t
).
Figure 11.3
shows some typical experimental curves.
The two autocorrelation and cross-correlation curves are fitted according to
Eq.
(11.5)
. Since we define the direction of line scanning to be the
x
-axis, so perpen-
dicular to the membrane, diffusion along the
x
-axis can be neglected due to the lim-
ited thickness of the plasma membrane (3-10 nm) in relation to the e
2
radius of the
detection volume (
250 nm).