title: Preparing compound heterozygous reference material using gene synthesis technology: a model of thrombophilic mutations.
abstract: OBJECTIVE
  The aim of our study is to present a novel approach for preparing a compound heterozygous reference material (hetRM) using gene synthesis technology with inverted insertion of wild-type and mutant fragments into a single cloning vector. Factor II (G20210A) and Factor V (G1691A Leiden) gene mutations were used as an experimental model.
  
  
  METHODS
  During the gene synthesis, DNA fragments were aligned in the following order: G1691 FV wild-type forward strain, G20210 FII wild-type forward strain, 1691A FV mutant reverse strain, 20210A FII mutant reverse strain. The complete chain was inserted into a pIDT SMART cloning vector and amplified in an E. coli competent strain. For assessing hetRM characteristics and commutability, we used real-time PCR with subsequent melting curve analysis, real-time PCR with hydrolysis probes, allele-specific amplification, reverse hybridization, and dideoxynucleotide DNA sequencing.
  
  
  RESULTS
  All five methods yielded concordant results of DNA analysis of the hetRM. Differences in real-time PCR cycle threshold values after six-months of storage at -80 °C were not statistically significant from those obtained from freshly prepared hetRM aliquots, which is a good indication of their stability.
  
  
  CONCLUSIONS
  By applying the procedures of gene synthesis and cloning technology, we prepared and verified a model genetic reference material for FII G20210A and FV G1691A testing with a compound heterozygous genotype. The hetRM was stable, commutable, and available in large quantities and in a wide concentration range.
authors: Institute of Clinical Biochemistry and Diagnostics, Faculty of Medicine in Hradec Kralove, Charles University in Prague and University Hospital Hradec Kralove, Czech Republic.
authors: Martin
authors: M
authors: Beranek
authors: Monika
authors: M
authors: Drastikova
authors: Petr
authors: P
authors: Dulicek
authors: Vladimir
authors: V
authors: Palicka
mesh_terms: D019976:Cloning, Organism / Q000379:methods*; D004926:Escherichia coli; D005165:Factor V / Q000235:genetics*; D005821:Genetic Techniques; D009154:Mutation; D011516:Prothrombin / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D019851:Thrombophilia / Q000235:genetics*
chemical_list: D005165:Factor V; D011516:Prothrombin