DNA, 10 pmol of each primer, 4 nmol of each deoxynucleotide, 1.5 U of Taq DNA
Polymerase (Sigma-Aldrich, USA), 1 × PCR reaction buffer (containing 15 mM
MgCl2; Sigma-Aldrich, USA) and additionally 25 mmol MgCl2. PCR
products were further purified with thermosensitive Exonuclease I and FastAP
Alkaline Phosphatase (Fermentas, Thermo Fisher Scientific, USA) and sequenced
with BigDye® Terminator v3.1 Cycle Sequencing Kit on an ABI Prism 3130XL
Analyzer (Applied Biosystems, Foster City, CA, USA) according to the
manufacturers’ protocols.
The sequences were compared between cases and healthy family members and the
general population separately for N. meningitidis and
S. pneumoniae cases.
The study was performed with the approval of the Poznan Medical University
Ethical Committee and a written informed consent was obtained from all of the
parents.