Trace data are rarely available in public EST databases. When trace data are not present, SeqMan Pro cannot remove the poor quality data using the Trace Quality Evaluation system. However, you may still remove questionable quality data from EST reads using the fixed end trimming option or the Quality trimming option, with a maximum frequency of Ns specified. If you know which vectors were used for EST sequencing, you may perform vector trimming also. Whenever trace data are available, it is recommended to trim poor quality data using the Trace Quality Evaluation system.