Techniques In Cell Biology Flashcards
What is cell fractionation?
Process used to isolate cellular components to study their structure and chemical composition.
What are the two main steps involved in cell fractionation?
- Homogenization
- Sedimentation
What is the purpose of homogenization in cell fractionation?
First step of cell fractionation where similar types of cells are broken in an ice-cold, suitable medium with proper pH and ionic composition.
What method is used to break cells during homogenization?
Cells are placed in a homogenizer or ground using mortar and pestle.
What enzyme is used to digest the middle lamella in plant cells during homogenization?
Pectinase
What is sedimentation in the context of cell fractionation?
Separation of cell organelles based on density and mass through centrifugation.
What type of centrifuge is commonly used in sedimentation?
Ultra centrifuge (up to 60,000 rpm)
What happens during stepwise centrifugation?
- Low speed: larger particles (e.g., nuclei) settle first.
- Higher speeds: progressively smaller particles separate.
What is the purpose of the supernatant in sedimentation?
It is re-centrifuged to isolate finer particles.
What is differential staining?
Technique that uses different dyes that bind based on chemical composition to distinguish various cell types.
What is the significance of using more than one dye in differential staining?
Helps distinguish various WBC types or other cells.
What is the technique of microdissection used for?
Isolate specific cells using a microscope for biological research.
What areas of study can microdissection be used in?
- Embryonic cell development
- Chemical effects on cells
- Treatment of diseases
What is tissue culture?
Cloning technique for cells or tissues in artificial medium.
Why can plant cells be cloned in tissue culture?
Because plant cells are totipotent (can grow into a complete plant).
What did F.C. Steward achieve in 1958 regarding tissue culture?
Grew a carrot plant from a tiny phloem piece in a medium with sugar, minerals, vitamins, and coconut milk.
What components were included in the medium used by F.C. Steward for growing carrot plants?
- Sugar
- Minerals
- Vitamins
- Coconut milk (contains plant hormones)
What was the result of F.C. Steward’s tissue culture experiment?
Cells divided and formed a new plant.
