Karyotype
Characteristics chromosome complement of a eukaryote species
In normal autosomal chromosomes
Present in 2 identical copies
May or may not be sex chromosomes
Polyploid Cells
Multiple copies of chromosomes and haploid cells have single copies
Karyology
The study of whole sets of chromosomes
Nuclei and chromosomes inside
Traditional process for karyotyping
Adding a dye to metaphasic chromosomes
Different dyes that affect of the chromosomes are used for
range of identification purposes
Such as diagnosing Down Syndrome
One common dye used is
Giemsa
Giemsa is the process known as
G-Banding
Why is the dye effective?
It markedly stains the bands on a chromosome
Each chromosome can be identified by
Banding pattern
Result is similar overall gray values for each a chromosome
Karyogram or idiogram
In pairs, ordered by size and position of centromere for chromosomes of the same size
New karyotyping methods
Fluorescent dyes that bind to specific regions of chromosome
By using series of specific probes each with varying amounts of dyes
Different pairs of chromosomes have unique spectral characteristics
Pairing of the chromosome is simpler because….
Homologous pairs are the same color and aberrations and cross-overs are more easily recognizable
