chapter 30 - cytogenetics

using Giemsa stain

G-banding refers to the technique of staining chromosomes:

demecolcine

compound that is used to halt mitosis in metaphase for chromosome analysis

band 1

one arm of chromosome has 30 bands

which band would be nearest the centromere?

must be performed on dividing cells

not an advantage of the use of FISH

• can be used on nondividing cells

• can be used on paraffin-embedded tissue

• can detect mutations that do not result in abnormal banding patterns

• must be performed on dividing cells

point mutation resulting in a single amino acid substitution

type of mutation that would likely not be detectable with cytogenetic banding techniques

loss of genetic material from a chromosome that does not appear on any other chromosome

describes a chromosomal deletion

loss of a portion of the long arm of chromosome 5

chromosome analysis performed on px’s leukemic cells —- 47, XY, +4, (del)(5)(q31)[20]

what abnormalities does the px’s cells have?

an extra chromosome 4

chromosome analysis performed on px’s leukemic cells —- 47, XY, +4, (del)(5)(q31)[20]

what other mutation is present in px’s cells?

both structural & numeric chromosomal defects

chromosome analysis performed on px’s leukemic cells —- 47, XY, +4, (del)(5)(q31)[20]

the px’s leukemic cells demonstrate:

that reflects a loss or gain of a single chromosome

aneuploidy describes the total chromosome number