This figure, adapted from Suzuki et al., 2001 (European Journal of Cell Biology)
shows immunofluorescence microscopy of MDCK cells (Marine-Darby canine kidney
cells). The kidney expresses sodium-glucose symporters (SGLTs) to recover glucose
in urine (we'll cover on Wednesday). Remember that immunofluorescence
microscopy allows us to see the location of a protein in a cell using primary and
secondary antibodies.
The data in these pictures are separated by row and distinguished by what proteins
are being detected. In the middle column (h,k,n), they are always visualizing SGLT1
using a secondary antibody that fluoresces green. In the right column, they change
which protein they are looking at (i = claudin; l = gp135; o = Na+/K+-pump) using a
secondary antibody that fluoresces red. In the left column (g,j,m) - they are overlaying
the two pictures (for example, g = h+i). This box is usually called an overlay or a
merge. Note: gp135 is an apical glycoprotein.
g
h
i
j
k
l
m
n
o
Adapted figure legend: Localization of SGLT1 in MDCK cells. Semi-frozen sections
were cut and stained with anti-SGLT1 (h,k,n; green), anti-claudin (i; red in g),
anti-gp135 (l; red in j), and anti-Na/K-ATPase (o; red in m). DAPI (blue) was used for
nuclear DNA staining. Bar = 20 um).
Let's work through interpreting this data:
1. What do the bright areas in h, i, k, l, n, and o represent?
2. What does it mean if the bright areas overlap in h+i, k+l, and n+o? (Note:
typically these areas will look yellow in the overlay image)
