3.4 Locate Lane Boundaries

The left and right boundaries of each of the lanes in the image are determined automatically. The number of lanes identified is based on the number of lanes defined in the gel-format file. After the program performs its automatic-detection process, which takes only a few seconds, you may accept the results or you may "edit" or adjust the lane boundaries. When you are finished, each lane is labeled.

• Pointer to Operations Submenu, click [Lanes] . Automatic lane demarcation is performed.

• When the automatic portion is finished, the Status Information Region directs you to use the mouse buttons to add and delete lane boundaries or to accept the current boundaries.

• To accept the lane boundaries as is, click MB3. Otherwise, you may edit the boundaries:
  - To remove a lane boundary, move the pointer over the lane boundary and click MB2. The boundary disappears.

  - To add a lane boundary, depress MB1 in the vicinity of where you would like the boundary. A vertical line will appear that can be moved for precise placement. While MB1 is depressed, move the pointer to the exact location and release MB1. The new boundary is fixed. If you don't get it quite right, delete it with MB2 and add it again with MB1.

  - When you have finished editing, click MB3.

• If lane boundaries have been added and/or removed, and if the total number of lane boundaries is not an even number, a warning message is issued. Likewise, if the number of lanes does not equal that of the gel-format file, a warning message is given. Warning messages appear in the Status Information Region. In either case, you may re-enter the edit phase by clicking \fbox{Lanes} again. Should you do so, the automatic portion is skipped; and you may edit immediately. Lane errors must be corrected in some manner.

• If the lane-detection algorithm does not perform satisfactorily, it may be advantageous to perform the image cropping again (see Section 3.3).

• When MB3 is clicked and the number of lane boundaries is even, two stripes of labels appear above or below the cropped image (see Figure 3.6). Placement above or below depends upon the space available.
  - The lane-index stripe, the stripe adjacent to the image, contains lane index numbers (0 to N, where N is the number of lanes). On color displays, this stripe is blue.

  - The other stripe, the lane-label stripe, contains the lane labels from the gel-format file. However, only the last 2 characters of each label are displayed. The lanes labeled "M" are marker lanes or size-standard lanes. On color displays, this stripe is green.

  - The lane-index stripe and lane-label stripe may be moved or turned off. To the right of the image is a scrollbar. Above the scrollbar are 3 tiny colored buttons. The middle button (blue on color displays) is a 3-way toggle for the lane stripes. The 3 positions are "above" the image, "below" the image, and "off".

  - If inheritance is active, a third stripe (inheritance stripe), containing family relationship codes, is treated as the other two stripes.

Figure 3.6: Image with lane boundaries, lane-index stripe and lane-label stripe.