Warning: Be sure both UV lamps are off before opening the
gel tray or camera enclosure door (retinal hazard).
Open the camera enclosure and position the gel in the center of the
light tray, close the camera enclosure and turn on the transmitted
ultraviolet illumination (TRANS UV).
Acquire a good image of your gel under UV illumination by following the step indicated
around the Gel Doc XR interface.
Step I These controls are used for used for controling the
camera. They should be set correctly and rarely need adjustment.
Step II Set the 'Image Mode' to UV.
Step III Select 'Auto Exposure.' The camera will begin
from a very short exposure time and slowly increase the exposure until it finds
a reasonable exposure; the image of your gel will slowly emerge from darkness
as this happens. As the camera finds the optimal exposure, the exposure time
will stop increasing (watch the black bar in the lower right corner for
exposure progress). When the camera reaches optimal exposure, you can click
the 'Freeze' button to stop the camera. For most gels, the software will find
the correct exposure. If you're not sure about the exposure, you can click the
'Manual Acquire' and adjust the exposure manually.
Step IV These tools allow for the adjustment of the
image and are optional. For densitometry, it is imperative that your bands
are not saturated. Click the 'Highlight Saturated Pixels' to have the
software identify saturated pixels in red. It is fine if there is some red
around the edges of the gel or in the well, but you'll need to avoid
saturation in your bands. When you are satisfied with your image, be sure to
uncheck 'Highlight Saturated Pixels' before proceeding with the analysis.
Use 'File' -> 'Print' to print an image of your gel or 'File' -> 'Export as JPEG' to save an image of
your gel. Be sure to set the image quality to 100.