- Created by: Hpgrice
- Created on: 29-10-19 17:54
What is cyto-genetics?
- Chromosome Analysis
- FISH test e.g. TBX1 gene in Chromosome 22 for Di George syndrome (most common microdeletion syndrome in the world)
- MLPA - Multiplexing PCR so mutliple tests can be ran on the same sampel
- Quatitative Fluorescent-PCR
- array CGH/SNP array
Cyto-genetics resolution is 5Mb and usually used cell culture and microscopy where as molecular genetics is 1bp and used DNA extraction and PCR.
Primary tissues for testing: blood, bone marrow, amniotic fluid, chorionic villus biopsies, skin biopsies.
37'C incubator, media that includes nutirents required and growth factors. For blood PHA which stimulates T-cells. Then add Colcemid (derived from kidney beans) to stop cell division at metaphase. The cells are then processed and the suspension is put onto a slide to view under the microscope or use a slide scanner which finds 120 metaphases per patient which reduces time.
Short arm = p (petit) and long arm = q
1.Metacentric - p arm and q arm are approx the same length e.g chromosomes 1,3,16,19 & 20
2. Sub-metacentric - p arm shorter than q arm e.g 4,5,17,18, most others
3. Acrocentric - satellite structure present on p arm, p arm very small e.g 13,14,15,21,22
X and Y are sex chromosomes, all others are autosomes
- Pre-treatment with proteolytic enzyme trypsin
- Dark bands…