1a. Cyto technical

Question 1

What sort of tube do you need for cyto analysis?

Answer 1

Green top with sodium heparin

Green >Grow

Question 2

Describe stages of cell preparation for cyto studies

Answer 2

Question 3

What is the cell synchronization technique?

Answer 3

• culture in usual manner for 48hrs
• add methotrexate and incubate 17hrs (cells stalled at G1/S)
• release methoterexate block by replacing media with complete media including thymidine (4-6 hrs) to get the cells to prometaphase
• add colcemide for 10-15 mins
• proceed to harvest

Question 4

in constitutional karyotype, how many cells do we analyze? how many karyotype? what to record?

Answer 4

Blood and tissue: 20 cells analyze 2 karyotype
(or at least 1 cell per clone)
Record: chr number, cell coordinate cell identifier, other comments

Question 5

where do we grow amniotic fluid?

Answer 5

coverslips

Question 6

If abnormality is seen in one entire volony but not other colonies it is likely…….. (culture artifact)

Answer 6

pseudomosaicism

Question 7

What is the difference between growing cells on coverslip and flasks?

Answer 7

for amniotic fluid we use coverslips, it gives info about origin of colonies since ther are no cell passage

Question 8

What does each staining technique stain?

G-banding (Giemsa):
C-banding (Giemsa):
R-banding (various stains):
Q-banding (quinacrine):
NOR staining (silver stain):

Answer 8

G-banding (Giemsa): Standard for most chromosome analysis* Light bands are GC-rich
C-banding (Giemsa): Identifies heterochromatin (centromeric and elsewhere)
R-banding (various stains): Opposite pattern to G-banding (dark bands GC-rich)
Q-banding (quinacrine): Used in past for polymorphisms NOR staining (silver stain): Stains ACTIVE nucleolar organizing regions on acrocentrics

Question 9

clones are….or more cells with the same structural or numerical abn and ….cells for loss of chr

Answer 9

2
3

Question 10

clones in karyotype:
….clone listed first, ….clone listed last
Abnormal clone listed in order of…..

Answer 10

abnormal, normal
size (highest first)

45,X[15]/47,XXX[10]/46,XX[23]
(exception = cancer cells with stem line)

Question 11

What is the nomenclature for Robertsonian translocation?

Answer 11

45,XX,der(13;14)(q10;q10)