BTSeq™ Contiguous Sequencing Service

BTSeq™ Contiguous Sequencing Service

„Sanger-type“ templates but upto 20 kb and using Illumina technology.


BTseq ™ (Barcode-Tagged Sequencing) is a special sequencing method for Illumina sequencers, which allows very cheap sequencing of "Sanger" type templates - plasmids, pcr products but also small genomes of bacteria or viruses. The method is based on the use of special chemistry and specific procedures for the analysis of the obtained data.


Template size up to 20 kb!

BTSeq™ sequencing service provided based on our contract with


BTSeq applications:

  • Long-range PCR amplicons
  • Plasmids
  • mtDNA
  • Small genomes

Features & Benefits:

  • Efficient analysis without the use of sequencing primers
  • Full length sequencing results for sequences up to 20 kb
  • Fast sequence analysis using proprietary molecular barcode technology and NGS error removal



Wide range of DNA size

  • up to 20 kb or more*
  • Plasmid sequencing with large insert DNA
  • NGS-based high data quality
  • Digitized sequencing results


Most affordable price

  • Unparalleled cost-effectiveness compared to Sanger and conventional NGS regardless of DNA size
  • No need of primer walking for de novo DNA sequencing
  • Eliminating the need of primer synthesis



No restrictions in samples and origins

  • Compatible with unpurified PCR products
  • Low amount sample requirements - 40 ng
  • Sequencing samples of various species 

* Longest template we tested so far: >50 kb. Contact us in case of interest.


Results and guarantee

For each sample that passes the initial quality control you will obtain (well known) data files like for Sanger sequencing:


Consensus sequence in fasta format


Base frequency table showing frequency of every base in the given position of the consensus sequence:

ab1 file visualizing the consensus sequence:

Sequence >3000 b will be split into several ab1 files.


Example of data files – feel free to download results for one of test samples!


What you should know:

  • Do I get results in the standard NGS format, typically fastq? - Not by default. On request, in the future it will be possible to process the outputs in a different format than stated above, but at the moment it is not possible.
  • What is the reading accuracy / error rate of the BTSeq method? - Samples are sequenced on Illumina instruments, which in itself ensures the highest possible reading accuracy. The consensus sequence is created using a de-novo assembly, where the parameter of reliable determination of the base at a given position is at least five reads, however the capacity per sample is set so that the average coverage is about 150x, so the accuracy of the assembly is very high even for positions with more variants.
  • How will it affect the results if it is a mixed sample? - As with Sanger sequencing, it is very important for the BTSeq method that the template is not mixed. The Sanger method gives an unreadable electropherogram if the template is a mixture. When using BTSeq, you only get the consensus sequence of the template that has a higher representation in the sample, even if the difference in representation is minimal. The base frequency table in particular will be informative in these cases. It is therefore possible to sequence mixed samples, but given this limitation and in principle we do not recommend it!
  • What does the absolute number in each row of the base frequency table say? - Shows the frequency of occurrence of one of each of the four bases, as it was assigned to a reference assembly (sequence) at a given position after deduplication of the reads and their mapping.


Processing time

Time to results is approx. 2 weeks!

Sample requirements

Follow our Sample submission guidelines. The samples must be delivered exactly in the concentration according to instructions! Please note that, as with Sanger sequencing, we do not verify the concentrations of the delivered samples with the BTSeq method!

  • dsDNA – PCR products and plasmids or genomic DNA
  • Size <20 kb
  • Concentration and volume: 2-5 ng/ul, 20 ul
  • Standard purity, PCR products can be unpurified
  • If sequencing PCR products or plasmid inserts, provide us with information about their size and primer F and R sequences
  • If sequencing plasmids, provide us with information about their type, size, and insert size

You will enter all the necessary information when filling out our order form.

How to order the service

The analysis can be ordered and commissioned online as a package for 24, 48, 94 or 190 samples. If you want to order an analysis of a different count of samples, contact us to prepare an individual calculation.




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