Sequencing of PCR amplicons to study genetic variation within small target regions. The method involves two PCR steps:

  1. Amplification of specific locus using target-specific primers equipped with universal overhangs.
    Performed by the facility user.
  2. Reconstitution of sequencing adapters (artificial sequences carrying motifs necessary for the analysis) and incorporation of unique sequence identifiers (barcodes / indexes).
    Performed by NGSf staff.

General workflow

general workflow


Overhang sequences for targert specific primers

FW primer: 5'-ACACTCTTTCCCTACACGACGCTCTTCCGATCT–[target-specific sequence (optimaly 20bp)]
RV primer: 5'-TGACTGGAGTTCAGACGTGTGCTCTTCCGATCT–[target-specific sequence (optimaly 20bp)]

Sequencing analysis conditions

  • Sequencing output: 2 × 150bp or 2 × 250bp Illumina paired-en reads (fragment sequenced from both sides)
  • Data amount: 105 - 107 sequenced fragments (depending on requirements)
  • Turnaround time: 2 - 3 weeks for 2 × 150bp, 3-4 weeks for 2 × 250bp
  • Frequency: monthly
  • Collection of samples: within first week of a month, shipment in the first part of following week

Sample submission guidelines

  • Sample Type: Purified PCR fragment of interest (amplified with suitable primers), and eluted in water or TE.
  • Sample Amount: >0.25 ng/µl.
  • Sample Volume: 10 µl.
  • Sample QC: Information about the concentration an volume + gel image or output from fragment analyzer.
  • Maximum number of samples/plate: 94. When using a plate, leave the last two wells in column 12 empty (do not add water or buffer).
  • Sample naming: samples must be described as follows “GRP_USR_01”, where GRP represents first 3 letters of the groupleader name, USR first 3 letters of the user name and last field is reserved for a 2 digits sample ID.
  • Sample submission form: Please first register your project in request form, then fill your samples into sample form

Guidelines for PCR1 (performed by the user)

  Reaction Cycling conditions
  5X Q5 Reaction Buffer5 µl   98°C / 30 s
  10 mM dNTPs0.5 µl 98°C / 10 s
  10 µM Forward Primer1.25 µl 50–72°C⁑ / 10–30 s (⁑25 cycles)  
  10 µM Reverse Primer1.25 µl 72°C / 20–30 s
  Q5 High-Fidelity DNA Polymerase       1.25 µl 72°C / 2 min
  Template DNAvariable* 4–10°C / hold
  Nuclease-Free Waterto 25 µl 
* need to be optimized for each combination of specific primers and template