6.1 Cell Biology Methods 1

Question 1

Primary cells

Answer 1

Removal of tissue or organs from animals/plants and grow in artificial aseptic environment. They undergo replicative cell senescence.

Question 2

Cell senescence

Answer 2

Phenomenon where normal diploid cells cease to divide. Ex: In culture, fibroblasts can reach a max of 50 cell divisions before becoming senescence.

Question 3

Immortalized cells

Answer 3

Population of cells from a multicellular organism that would normally not proliferate indefinitely but due to mutation, have evaded normal cellular senescence and instead keep undergoing division. The cells can therefore be grown for prolonged periods in vitro

Question 4

How do you generate a cell line?

Answer 4

• Isolation from naturally occurring cancer
• introduction of viral gene that partially deregulates the cell cycle
• artificial expression of key proteins required for immortality
• hybridoma technology specifically used for the generation of immortalized antibody producing cell lines

Question 5

Stem cells

Answer 5

Undifferentiated cell of a multicellular organism that is capable of giving rise to indefinitely more cells of the same type, and from which certain other kinds of cells arise by differentiation

Question 6

Advantages of studying immortalized cells in culture?

Answer 6

• divide continuously
• can be grown in vitro indefinitely
• can be cloned into a clonal population
• genetically identical cells

Question 7

Disadvantages of studying immortalized cells in culture?

Answer 7

• have undergone significant mutation to become immortal –> affects overall biology of the cell
• cell lines can change genetically over time
• contamination/overgrowth by other more aggressive cells is possible

Question 8

Normal cell behavior in culture

Answer 8

anchorage dependent and contact inhibited

Question 9

Cancer cell behavior in culture

Answer 9

anchorage independent and not contact inhibited

Question 10

hybridoma cells

Answer 10

Immortalized cell line derived from the fusion of B lymphoblasts with a myelon fusion partner

• capable of producing immunoglobulins specific for viral, bacterial or cellular targets
• yields a cell line capable of producing one type of antibody protein for a long time

Question 11

Hybridoma

Answer 11

Tumor from the immortal cell line of hybridoma cells

Question 12

How are stem cells different from other types of cells?

Answer 12

MULTIOPOTENT (differentiate into several cell types) + PLURIPOTENT (differentiate into all other cell types)

• can develop into any type of cell in the body
• start in the embryo as unprogrammed cells then become specialized
• can repair and replace tissue

Question 13

How do you prepare a cell suspension?

Answer 13

Enzymatic digestion using Trypsin or collagenase

Question 14

How can you “cell sort”?

Answer 14

1. By cell size
2. By fluorescence
3. Magnetic beads

Question 15

Gravity sedimentation

Answer 15

Density gradient = large cells at bottom, small cells at top

Question 16

Fluorescence activated cell sorter

Answer 16

Surface protein is marked by fluorescence and the fluorescent cells are sorted from non-fluorescent cells. The DNA is sorted by amount of florescence.

Question 17

Magnetic bead cell sorting

Answer 17

Magnetic bead with antibodies for the antigens on specific cells….when a magnet is applied, collects all the cells with those antigen receptors and leaves the cells without the antigen receptors.

Question 18

Laser capture microdissection

Answer 18

Laser cuts around a small region of interest on a slide. Limitations = very time consuming and requires high manual dexterity