Noisy data throughout the sequence with low signal strength


Very low signal - raw-website

Raw signal intensity close to base line


Vey low signal - electropherogram-website

Low signal-to-noise ratio throughout. Large peaks at 70 and 110 nucleotides obscuring the real sequence; these are dye blobs caused by unincorporated BigDye, which become apparent in weak sequence.




Possible causes


Low template concentration

Quantify the DNA template.¬†Ensure that the concentration is in the range specified on the “Sample Preparation and Submission” TAGC web page.

Degraded template

Prepare fresh DNA and re-submit for sequencing.

Inhibitory contaminant in the sample (salts, EDTA, phenol, ethanol)

Clean up template.

Insufficient amount of primer

Check primer dilution.

Inefficient primer binding

PCR template before submitting to sequencing. Redesign primer if necessary.

Degraded primer

Prepare a fresh stock.