Methods of chromosomal examination

• Karyotyping (see question No. 33 - Human karyotype, methods of its examination)
• Analysis of acquired chromosomal aberrations:
  • conventional staining of chromosomes with Giemsa dye solution only - detection of chromosome breakage results (acentric fragments, double minutes, dicentric chromosomes, ring chromosomes, chromosome breaks, chromatid breaks,...)
  • SCE (sister chromatid exchange) – using of BrdU during cultivation, differential staining of sister chromatids
• FISH (fluorescent in situ hybridization) (see question No. 32 – Molecular cytogenetics)

Microarrays (see question No. 32 – Molecular cytogenetics)

• NIPT (non-invasive prenatal testing):
  • analysis of cell-free DNA (cfDNA) fragments of fetus in maternal circulation (test performed from maternal blood sampling), used as a screening method to search primarily for chromosomal aneuploidies, sex of the fetus or Rhesus blood type
  • different modifications include also detection of microdeletions or even whole karyotype scan
  • 10 weeks of pregnancy or later
  • methods of analysis are different (different companies) – based on PCR, CGH-arrays or next generation sequencing