animal cell biotech

uses of cultured cells over intact organisms

isolate single cells to grow into clone colony, can manipulate cells, examine effect of treatments of intracellular events

advantages of using cultured cells over intact organisms

more homogeneous than cells in tissues, can control experimental conditions, no ethical issues

requirements for growing cells in culture

rich growth media, serum with growth factors, sterile conditions, correct pH and osmolarity, special solid surface

how is primary culture generated

established from animal tissues - cells extracted from tissue using a protease

how do we grow cells to form a primary cell line

cells grow in a monolayer in dish until space is filled, small number of cells need to be passaged and transferred to another dish to continue cell line growth

senescence in animal cells

most cells from an animal grow and divide for a limited period - around 50 doublings - then die

cell line def

culture of cells with indefinite life span

what happens when some cells escape senescence

said to be transformed - arises spontaneously through genetic changes - these form a cell line

characteristics of transformed cell lines

immortal, anchorage independent, less need for growth factors, motile, no contact inhibition of growth, tumourigenic, less differentiated

2 uses of animal cells

protein production, tissue engineering

polyclonal antibody

from several different B cell clones that recognise different epitopes

monoclonal antibody

from a single B cell clone that recognises a single epitope

how can two cells be used to make a hybrid

mouse tumour cells in culture are fused with mouse spleen cells to form hybridomas, these are used to produce monoclonal antibodies

uses of monoclonal antibodies

research - measuring/detecting specific proteins/antigens, disease diagnosis, therapy

stages in tissue engineering

design scaffold from biodegradable substance - expand cells from biopsy - seed scaffold with cells and allow grow - implant into patient

pros of ESCs

pluripotent so can form any cell in body

cons of ESCs

not genetically identical to patient, difficult to culture, ethical issues

adult SCs pros

genetically identical to patient, no ethical issues

adult SCs cons

form limited number of cell types, not available for all tissues

how are iPS cells made

skin cells removed from patient, reprogram cells so they become induced pluripotent stem cells, treat them so they differentiate into specific cell type & return to patient

pros/cons of iPS cells

fewer ethical issues & can use patients own cells, technically challenging & risk of cancer

how does direct reprogramming work

reprogramming of one somatic cell type directly into another cell type, doesn't need IPS state, achieved by expression of key TFs - uses viruses and CRISPR-cas9