Chromosome Studies - Special Stains
R-banding procedures produce the reverse or opposite banding pattern as G-banding and Q-banding and denotes the GC-rich euchromatic regions. R-bands are important for detecting minor inversions, for comparing length of homologs, for examining the ends of chromosomes, and for identifying subtle deletions or rearrangements that may go undetected using G- or Q-bands.
Q-banding methods produce fluorescent bands after staining chromosome preparations with quinacrine. These bands represent the AT-rich regions of the chromosome and are analogous to the bands produced by G-banding. Q-banding is particularly useful in identifying polymorphisms on the satellites of the acrocentric chromosomes and of the Y chromosome, and in confirming translocations involving the Y.
C-banding is a procedure which stains the constitutive heterochromatin that is localized in pericentromeric regions of all chromosomes and on distal long arm of the Y. C-banding is useful in confirming pericentric inversions and in identifying polymorphisms of the centromeric regions of chromosomes 1, 9 and 16 and the heterochromatic region of the Y, and in confirming translocations involving the Y.
NOR staining is a silver staining procedure which stains the nucleolus organizer regions (NORs) of satellited chromosomes. It is particularly useful in studying variations in the size of the stalks and satellites of the acrocentric chromosomes.
DAPI staining produces bright fluorescence of the heterochromatic regions of chromosomes 1, 9, 16, Y, and the centromeric region of 15. It is particularly helpful in identifying the origin of small bisatellited marker chromosomes and in confirming translocations involving the heterochromatic region of Y.
|Specimen Requirements||Special staining may be added to any chromosome study. Please contact the lab (1-800-473-9411) prior to requesting any specific stains. Specimen requirements will be specific to the sample type.|
|Transport||Please see requirements for specific tissue types|
|CPT Codes||each: 88283 plus appropriate codes for tissue type studied.|
|Cost||$120.00 for each stain|
The Cytogenetics Lab provides high quality analysis for the detection of both constitutional chromosomal aberrations as well as abnormalities related to hematological malignancies