Chromas is a free trace viewer for simple DNA sequencing projects which do not require assembly of multiple sequences. Chromas has the following features:
- Opens .ab1 chromatogram files from Applied Biosystems DNA sequencers.
- Opens SCF and ZTR format chromatogram files created by other sequencers or retrieved from databases.
- Save in .scf or Applied Biosystems .ab1 format.
- Print a chromatogram with options to zoom or fit to one page.
- Automatic removal of low-quality sequence (when quality data is available) or vector sequences.
- Export sequences in plain text, FASTA, FASTQ, EMBL, GenBank or GCG formats, or formatted with base numbering for presentation.
- Copy the sequence to the clipboard in plain text, FASTA or FASTQ format for pasting into other applications.
- Reverse & complement the sequence and chromatogram.
- Search for subsequences by exact matching or optimal alignment.
- Display translations in 3 frames along with the sequence.
- Copy an image of a chromatogram section for pasting into documents or presentations.
- Batch processing, including format conversion, sequence export with vector removal, batch printing and batch export of raw data.
- Enhance .ab1 files using the PeakTrace RP component from Nucleics Pty Ltd to improve peak readability and extract more high-quality bases.
Compatible with Windows XP, Vista, 7, 8, 10.
Chromas is free of charge. The PeakTrace RP component is a paid service after the 20 free units have been used. An introductory discount is available by following the link under the Options menu in Chromas.
Version 2.6.4 keeps Chromas open if the user tries to exit while a PeakTrace batch operation is still in progress.
Version 2.6.3 has the following changes:
- Fixed a command-line bug which opened the first file twice if a switch was used.
- Fixed missing colors on the color selection buttons until clicked.
- Added automatic detection of the longest reading frame for translation display.
- Duplicated the vector removal setting in the main settings dialog.
- Added trimming options to batch conversion.
- Added a reverse+complement button in addition to the menu and shortcut commands.
Version 2.6.2 fixed a potential crash on exiting the program.
Version 2.6.1 was a minor update which improved handling of corrupt files, fixed help display from network drives, added scrolling with the left/right arrow keys, and added parallel PeakTrace processing for paid users.
Version 2.6 introduced PeakTrace functionality which can significantly increase the length of usable sequence extracted from your ABI sequencing reactions.
Version 2.5.1 fixed a potential security issue with .ab1 files which contain no sequence.
Version 2.5.0 was a major revision with the following changes:
- 32-bit and 64-bit versions.
- Unicode character set for internationalization.
- Improved handling of .ab1 and .scf files.
- Added FASTQ export format.
- Added ZTR format and removed support for legacy MegaBace format.
- Improved vector sequence database.
If you need to assemble multiple overlapping sequence reads, please see ChromasPro.