DNA sequencing as easy as 1, 2, 3!

Our HelixScan DNA Sequencer is a Macintosh-based software package that lets you produce accurate, reliable sequences in three easy steps. Just scan your film using a gray-scale hand scanner or any flatbed scanner, save the image as a TIFF file, and open it in the HelixScan program.

1. Set up sequencing parameters.

The HelixScan DNA Sequencer uses the standard Macintosh click-and-drag interface to define lanesets and lanes, adjust for smiles, edit DNA sequences, and copy and paste to theclipboard. A dialog box enables the setting of thresholds that serve as detection levels for accepting bands in the DNA sequence. Gel loading orders can be changed, along with the colors that represent the lanes and band markers on the screen. All the settings are saved in a preferences file for convenient recall during future experiments.

2. Sequence the laneset.

User-controlled options customize the sequencing algorithms. Lanes are correlated to provide uniformity among the interband spacings and resolve bands that may be partially obscured by bands in other lanes. The filtering option removes shadows and selects the strongest band, flagging it as a possible ambiguity. Called bases are entered into a standard text window, and the corresponding bands are marked and/or numbered in the image for easy reference. Correlated cursors between the text and image window allow you to visualize the location of a band in the DNA sequence.

3. Edit the sequence.

The easy-to-use edit tool makes adding a base as simple as clicking the mouse button.

Moving the cursor in the image highlights the closest band entered in the sequence. Clicking the mouse button then enters a new base directly after the highlighted band.

The Mac-based HelixScan system saves its acquired image files in the commonly used TIFF format and its generated sequences in the standard TEXT format, making it easy to export them into other analysis packages. Optional printing to color-output devices provides easy lab-book access for cross referencing in later sequencing projects.

• specifies loading order
• finds lanes and lanesets
• accepts curved lanes
• straightens smiles
• displays raw image data
• provides image and sequence views
• highlights ambiguities