U7: KARYOTYPE STAINING PART 2 Flashcards
5 Major Steps of Karyotyping
- Short term lymphocyte culture
- Harvesting of lymphocytes
- Fixing the cells
- Making the chromosome slides
- Slide analysis
Short term lymphocyte culture
What component do we need from peripheral blood?
Lymphocyte
Short term lymphocyte culture
Collected blood will be grown i__ v_____ by adding mediums.
In vitro
Short term lymphocyte culture
What medium/s is/are added to the cell culture?
- RPMI Growth Medium
- Fetal Bovine Serum
- Antibiotics
- Phytohemagglutinin
Short term lymphocyte culture
What reagent/s is/are used to lyse other cellular components in culture?
Hypotonic KCl solution, Glacial acetic acid
Short term lymphocyte culture
Density centrifugation is performed to acquire?
Buffy coat
Short term lymphocyte culture
What anticoagulant is used for collection of buffy coat?
Sodium Heparin tubes (Green)
Short term lymphocyte culture
This medium is selective for lymphocyte growth.
RPMI Growth Medium
Short term lymphocyte culture
Contents of RPMI Growth Medium
Amino acids, vitamins, bicarbonate
For the growth of cells
Short term lymphocyte culture
Contents of Fetal Bovine Serum
Source of albumin
Short term lymphocyte culture
What is considered a protein overlay?
Albumin
Pag maarte daw yung cells, kailangan ng protein overlay - amino acids (whole protein) na ang nasa RPMI and might need albumin
Short term lymphocyte culture
Prevents growth of microorganisms in cell culture
Antibiotics
T/F: Lymphocytes in cell culture is only a monolayer, which easily dies in unfavorable conditions.
T
Short term lymphocyte culture
What component in RPMI maintains the pH with CO2?
Bicarbonate (HCO3-)
Short term lymphocyte culture
This reagent also ensures that only leukocytes are present in the culture, and ensures lymphocyte growth.
Phytohemagglutinin (PHA)
Short term lymphocyte culture
How many days should the cell culture be incubated?
3 Days
T/F: Cells should be in the logarithmic phase upon harvesting.
T
Short term lymphocyte culture
What equipment should you use to check if the cells are in logarithmic phase?
Inverted Microscope
Short term lymphocyte culture
This phase is the exponential phase of growth.
Logarithmic phase
Short term lymphocyte culture
How many days before harvesting should you split the cell line for significant cell proliferation?
2 days
Short term lymphocyte culture
This refers to the first phase in which lymphocytes adjusting to their culture medium.
Lag phase
Short term lymphocyte culture
How many days before harvesting should you change the medium?
1 day
Short term lymphocyte culture
Specific antibiotics to be used
penicillin-streptomycin antibiotics
Step 2 of Karyotyping
Harvesting of Lymphocytes
Harvesting of Lymphocytes
This reagent arrests cells at metaphase.
Colcemid (Colchicine)
Harvesting of Lymphocytes
How many minutes should you incubate the culture after adding pre-warmed colcemid?
15 mins
Harvesting of Lymphocytes
Optimal exposure time to colcemid requires a balance between?
proliferative activity index and colcemid concentration
Harvesting of Lymphocytes
This varies whether they are fast replicating or slow replicating
Colcemid concentration
Harvesting of Lymphocytes
Cells with high proliferative index requires shorter/longer exposure to a high/low concentration
shorter, high
Harvesting of Lymphocytes
Slowly growing cells requires shorter/longer exposure to a high/low concentration
longer, low (even overnight)
Harvesting of Lymphocytes
Prolonged exposure to colcemid increases proportion at what stage, and results into?
late metaphase, shortening of chromosomes
Harvesting of Lymphocytes
After colcemid treatment, cell pellets undergo what treatment?
hypotonic treatment
Harvesting of Lymphocytes
Hypotonic treatment uses?
- KCl solution (0.54%)
- Sodium Citrate
20 mins at 38C
Harvesting of Lymphocytes
Before hypotonic treatment, the culture must be centrifuged at ____ RPM for how many mins?
1000, 10 mins
Harvesting of Lymphocytes
Resuspension in KCl is used to?
lyse lymphocytes to isolate nuclear contents
Harvesting of Lymphocytes
After hypotonic treatment, incubate the solution at room temperature for?
15 minutes
Harvesting of Lymphocytes
Optional additional modifications that allow for enrichment of long prometaphase chromosomes
- Actinomycin D
- Ethidium bromide (added before harvesting)
- Bromodeoxyuridine or BRU (added before colcemid treatment)
Harvesting of Lymphocytes
These are mutagens that interfere with replication
Ethidium bromide and BrdU
Harvesting of Lymphocytes
This can significantly increase total yield of metaphase chromosomes
Cell synchronization