The signal is not long and the signal value is in poor quality

Status descriptions

  • The peaks look disordered and rough.
  • The signal stops before 800 bp

Possible reasons

  • There are too little template DNA
  • BigDye reagent is excessively diluted.
  • There are too many primers.
  • The DNA quality is poor.
  • Special fragments exist which make successful sequencing unavailable.


  • Check whether the DNA concentration is proper.
  • Check whether the BigDye dilution concentration is proper.
  • Check whether the sequencing primer concentration is correct.
  • Check the DNA quality.
  • Use Secondary construct reagent to solve the problem of special sequence. During the sequencing reaction, add 7-deaza-deoxy guanosine triphosphate (7-deaza-dGTP) to help the polymerase pass through GC-rich area.