CYTOGENETIC TECHNIQUES Flashcards
- Study of the physical size and structure of chromosomes
- A specialized laboratory discipline that examine the structure and behavior of chromosomes at the cellular level
Cytogenetics
cells are arrested in what phase of mitosis?
end prophase or in early
metaphase
cells are arrested in end prophase or in early metaphase of mitosis because of
- Compact and densely staining of chromosomes
- Characteristic size and shape of chromosomes
- Checks the number of chromosomes in the normal diploid cell
- Check the size distribution
Karyotype
Comparing chromosomes are based on:
- Length
- Location of centromeres
- Location and sizes of G-bands
Two Cytogenetic Techniques
- Classical or Standard Cytogenetic
- Fluorescence in situ hybridization (FISH)
Allows visualization of loss or gain of material
Classical or Standard Cytogenetic
- Allows much smaller changes to be seen
- Far more advanced
Fluorescence in situ hybridization (FISH)
Blood additives
EDTA, ACD
what is EDTA?
EthyleneDiamineTetraAcetic Acid
- Prevents the coagulation of blood
- Allows the qualitative and quantitative determination of HIV, Hepatitis C and Cytomegalovirus (CMV)
EDTA
- Prevents the coagulation of blood
- Preserve the form and function of cellular components
Acid Citrate Dextrose
top color of EDTA?
purple top
top color of ACD?
yellow top
- Uncommon
- Used for:
- Bladder cancer screening
- Monitor therapy of bladder cancer
Urine
type of urine used
midstream
how much urine is needed?
first 10ml
- Differential and quantitative analysis as a sensitive specific biomarker for the detection of colorectal cancer
Feces
- Rapid identification of infectious agents
- Comes from brain and spinal cord
Cerebrospinal Fluid
how many tubes are used in CSF? what tube is used?
4 tubes are collected; 2nd tube is used
why is the 2nd tube used for CSF collection?
it is the purest CSF specimen
normal CSF protein
50-80 mg/dL
0.18-0.45 g/L
normal CSF glucose
15-45 mg/dL
2.5-3.5 mmol/L
normal CSF RBC count
0 cells/mm3
normal CSF WBC count
0-3 cells/mm3
normal CSF xanthochromia (yellowish color)
none
normal CSF appearance
normal (water)
bacterial CSF appearance
turbid
viral CSF appearance
clear
fungal CSF appearance
fibrin web (clotting)
bacterial CSF protein
more than 1
viral CSF protein
less than 1
fungal CSF protein
0.1-0.5
bacterial CSF glucose
less than 2.2 mmol/L
viral CSF glucose
normal (2.5-3.5)
fungal CSF glucose
1.6-2.5
bacterial CSF WBC
more than 500