Exam II – 60 points
1. Identify the different sources of contamination? a. Failure in sterilization procedures for solutions, glassware and pipettes b. Poorly maintained incubators and refrigerators c. Faulty laminar-flow hoods d. Importation of contaminated cell lines or biopsies e. All of the above are possible sources
Mention most significant source of contamination. (2 points)
2. Mention the different contaminants found in cell culture experiments. a. Bacteria b. Yeast c. Fungi d. Molds e. All the above
3. You have to identify any contaminant if it is occurring frequently in your cultures – True/False.
Otherwise what are the important points you have to consider if the contaminant is not occurring frequently? (3 points)
4. Is it advisable to discard all you media, stock solutions and trypsin enzymes if any contamination is new and widespread? Yes/No
5. Is it advisable to never decontaminate and discard cultures unless it is irreplaceable? Yes/No
6. Name any two visible features of microbial contamination. (2 points)

7. Name any two molecular/microscopic techniques you would use to identify mycoplasma contamination in your experiment. (2 points)
8. What are cryptic contaminants? Are those always present in your cultures? (2 points)
9. Mention the source of viral contamination. a. Serum b. Tylosin c. Thymidine d. all of the above
10. Match the following: (10 points) a. Continuous culture _________ no of times culture has been subcultured b. Generation number _________ no addition or removal of anything c. Batch culture _________ no of doublings of culture d. Fed-batch _________ 502-520 base pairs e. Passage number __________ controlled feeding f. PCR band of Mycoplasma __________ continuous addition and removal g. Encapsulation __________ Cells + sodium alginate drip into calcium alginate h. Entrapment __________ Cells + warm agarose + paraffin oil i. Animal cell culture vessel __________ Flat bottomed j. Bacterial cell culture vessel __________ Round bottomed
11. Match the following (10 points)
A. Lineage markers _______________ differentiation gives rise to more than two lineages
B. Differentiation ________________ differentiate in more than one or more direction

C. Terminal differentiation _______________ loss of differentiated phenotype
D. Commitment ______________________ heterologous interaction
E. Dedifferentiation _________________ addition of glycoproteins and proteoglycans
F. Multipotent ______________ irreversible differentiation
G. Early progenitor cells ________________ cell progression cannot proceed beyond a point
H. Heterologous cell-cell interaction _________ hormones and vitamins
I. Systemic physiological factors ___________ expression of phenotype
J. Cell-matrix interactions ____________ measures levels of differentiation
12. If the stem cell is located in a specific tissue/ part of body, then it will commit to producing cells of that region only -True/False.
13. Explain any one pathway of differentiation and the problems associated with the same. (4 points).
14. Why do cell culturists scale-up their cultures? (2 points)
15. Name the four factors you want to control in your fermenter/bioreactor. (2 points)
16. Name the simplest and widely used type of bioreactor. (1 point) a. Stirred tank b. Airlift fermenter

c. Fixed-bed d. Hollow-fiber e. all the above
17. Name the material used in construction of large scale fermenters and small scale STRs. (1 point)
18. Animal and fungal/bacterial cell cultures are cultured in different types and design of bioreactors –
True/False.
In either case support your answer with a statement. (2 points)
19. Name the two types of continuous cultures. Name the differences involved between the two kinds.
(3 points)
20. What are micro carriers and mention any two of its characteristics? Can these be used in suspension cultures? (3 points)
21. Name any 2 factors that you will consider while choosing a cell line. (2 points)
22. What is holding media?
23. Choose the true statement for differences between suspension and monolayer cultures. a. No need of trypsin and frequent changes in media for subculture of suspension cultures. b. Agitation is needed in monolayer cultures

c. Agitation is not needed in suspension cultures d. Media is not changed but always diluted in subculture of monolayer cultures.
24. Mention any two points you that will make you want to subculture your cells. (2 points)
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