Cytogenetics is the study of chromosomes and the related diseases caused by numerical and structural chromosome abnormalities. Chromosome studies are important laboratory diagnostic procedures in prenatal and postnatal diagnosis. The results of the diagnosis provide important information for further medical interventions.
Chromosome studies can either be performed with the classical staining method or with molecular methods. The classical cytogenetic analysis is based on the banding pattern of dyed chromosomes. Therefore several banding techniques have been developed (e.g. Q-, C- or G-banding). Using molecular cytogenetics genetic diseases based on mutations, small deletions or insertions can be detected with Fluorescent In Situ Hybridization (FISH), Comparative Genomic Hybridization (CGH), PCR or DNA-Sequencing.
Karyotyping for classical chromosomal Analysis
For karyotyping metaphase chromosomes are prepared by subsequent cultivation in nutrient media and synchronisation of cells in metaphase with inhibitors (colcemid). The proliferation of non dividing blood cells such as lymphocytes in culture, is stimulated by the mitogen phytohaemagglutinin, providing a very accessible source of metaphase cells. Precise karyotyping allows the cytogeneticist to identify chromosome abnormalities from amniotic fluid or foetal tissue samples.
Cytogenetic products for In Vitro Diagnostics
Products used in In Vitro Diagnostics (IVD) are subjected to guidelines according to the directive 98/79/EC defined by the European commission on 27.10.1998. Several requirements like traceability, quality assurance, documentations, specific labelling and the declaration of conformity must be implemented into manufacturers total quality assurance system to ensure constant product quality. Since 7 December 2003 products used for IVD must be labelled clearly with appropriate special characters and symbols (e.g. CE or IVD).
Prenatal Diagnostics
For detection of genetic diseases karyotyping is an important procedure in prenatal diagnostics. Many diseases and birth defects are a direct result of missing, broken, or extra chromosomes. Amniocentesis and Chorionic Villus Sampling (CVS) are the most important prenatal diagnostic tests. They both involve culturing of isolated foetal cells in specific nutrient media enriched with growth factors and hormones, followed by chromosome analysis to detect chromosomal abnormalities.
Postnatal Diagnostics
In contrast to prenatal diagnostics where only limited amounts of foetal cells can be used the postnatal diagnostics have access to blood cells in sufficient quantity to prepare a karyotype. Since lymphocytes are not actively dividing, cell mitosis must be induced with the mitogen phytohaemagglutinin. For cytogenetic analysis proliferating lymphocytes of the peripheral blood are cultivated in specific media and intact metaphase chromosomes are prepared with classical or molecular cytogenetic methods.
PAA's complete Media
In the field of prenatal diagnostics, PAA can offer QUANTUM 3-21 and Ham´s F-10 Ready Mix, two complete media for quick and reliable diagnosis of chromosomal abnormalities.
For postnatal diagnostics we offer QUANTUM PBL, our ready to use medium with phytohaemagglutinin for culturing peripheral blood lymphocytes.
With QUANTUM 3-21 and QUANTUM PBL, PAA offers two "CE marked” media for IVD which fulfil the requirements of the directive 98/79/EC defined by the European commission.
Extensive quality control Tests
Extensive quality control tests assure constant high product quality. PAA manufactures cell culture products according to current GMP. Further quality control and quality assurance are carried out to the highest standards as required by the biopharmaceutical industry.