Advanced Cellular Biology - Lab quiz 1 - Dr Pearcy - Wayne State College

explain cell culture

growth of one cell type outside its natural environment through invitro growth of disassociated cells

how are cells in a cell culture disassociated?

using proteolytic enzymes to digest adhesion molecules in the extracellular matrix and Ca2+ chelating agents to disrupt CAMs

explain tissue culture

inclusion of intact tissue grown outside the body, may contain multiple cell types, done through primary explantation

what is primary explantation?

when tissue is taken directly from the organism

what are cell culture benefits?

- reproducibility in quantity and historically allowing for replication of experiments

- less invasive

- more ethically palatable

- cost effective, saving space, time, resources, etc.

what are cell culture detriments?

- specificity, lack of applicability to other cell types

- can't study how it is influenced or influences other cell types in the body

what is required for mammalian cells to grow in a culture?

- temperature regulation (37 degrees Celsius)

- pH balance (C02 regulation)

- basement layer for adhesion (collagen, laminin)

- nutrients (salts, vitamins, amino acids, provided by the media)

- serum (insulin, transferrin, and growth factors)

what other properties are needed in cell culture media?

phenol red (pH indicator), penicillin and streptomycin (prevent contamination)

explain normal cell longevity vs HeLa cell longevity

most cells have a finite lifespan due to gene deactivation or cell cycle arrest

HeLa calls are immortal due to the addition of deactivated genes, oncogenes, viruses, and chemicals because it is a culture of cancer cells

what types of cells are immortal?

stem cells and cancer cells

what are the characteristics of a stem cell?

must be capable of self-renewal, must differentiate into mature cells, be potent (potency can vary)

what are the four stem cell potency types? and an example of each

totipotent: can do it all (zygote)

omnipotent: can form all tissues in the body (stem cells)

multipotent: can form more than one tissue type (hematopoietic stem cells)

unipotent: can form only one cell type (skin cell)

explain the ethical constraints of embryonic stem cell research and who banned/lifted bans on this type of research

embryonic stem cell research was restricted by George Bush and then later revised by Obama stating existing embryonic stem cells could be used for research but new ones where not to be created, this was done out of worry for potential abuse of fertilized eggs with the potential to become humans

what form of "stem cell" research is being done now and why?

unfertilized eggs are being using by removing the haploid nucleus and injecting a diploid nucleus of another cell (lung cell, skin cell, etc.) the difficulty in this is getting the injected cell to first divide then after that they have had great success, this method is much more ethically palatable since the egg is not fertilized and does not have the potential to become a human