Fig. 8. HDLp exits CHO(iLR) cells with a t of 13 minutes. Living CHO(iLR) cells, preincubated with DiI-LDL and OG-HDLp, were observed in an aluminium chamber with confocal laser microscopy during a chase for 20 minutes. Digital photos were collected 10 minutes after initiating the chase at 2 minute time intervals (A-F) to visualize the intracellular distribution of LDL (red) and HDLp (green). To quantify the re-secretion of internalized fluorescently-labeled lipoproteins, CHO(iLR) cells were fixed directly after preincubation with DiI-LDL (filled circles) or OG-HDLp (open circles), and after a chase for 10, 30 or 60 minutes (G). Images were recorded using confocal laser scanning microscopy and analyzed with Scion Image software. The data points are geometric means of the measured relative intensity of total cells. Of each time point, 10 to 17 images were taken with 4 to 33 cells per image, corresponding to more than 200 cells per data point. The mean values were normalized to the measurement directly after the preincubation. The data were processed with Microsoft Excel and plotted with SigmaPlot. Bar, 20 µm; values are means±s.e.m. of 10 or more digital images.