Lab-1 Studying Death at Cell level Behzad Khoshnood, 2015
Slide 2
Cell death in multi-cellular eukaryotes Cell death
Necrosis
Slide 3
Development Homeostasis Immune survelliance Why is apoptosis
beneficial for the organism? Apoptosis and cell proliferation must
balance each other 5 X 10 11 blood cells are eliminated by
apoptosis every day Killing of virus infected cells between the
developing fingers
Slide 4
Cellular morphology changes during apoptosis Normal cell
Different stages of apoptosis Cell shrinkage Membrane ruffling DNA
condensation DNA fragmentation Phagocytic cells will recognize
phosphatidyl serine on the surface of the apoptotic cell and engulf
and degrade it
Slide 5
Apoptosis: Pathways Death Ligands Effector Caspase 3 Death
Receptors Initiator Caspase 8 PCD DNA damage & p53
Mitochondria/ Cytochrome C Initiator Caspase 9
Slide 6
The Fas/CD95/Apo-1 system in health and disease Fas Worn-out
cell Virus infected cell Tumor cell Cytotoxic T cell carrying the
Fas ligand on its surface Target cell killed through apoptosis upon
cell-cell binding Fas FAS ligand
Slide 7
JURKAT CELLS Established from a peripheral blood of a 14 year
old boy with T cell leukemia immortalized line of T lymphocyte
cells that are used to study acute T cell leukemia, T cell
signaling, and the expression of various chemokine
receptorsimmortalized lineT lymphocyteleukemiaT cell
signalingchemokine receptors Easy to handle, robust
growth(generation time~24hours) Presence of Fas receptor on the
surface. Interaction of Fas ligand/Fas antibody to the receptor
induces apoptosis
Slide 8
Fas Apoptosis Fas antibody, activates the Fas receptor Your
assignment To activate Fas-induced apoptosis using Fas antibody PMA
PKC Apoptosis CD3 Prolifration
Slide 9
Flow Cytometry Staining Western Blot (apoptotically-expressed
proteins) TUNEL assay (fluorescent microscopy) Luminescent and
Fluorescent Assays for Measuring Caspase Activity Microtiter plate
assay COMMON METHODS FOR MEASURING APOPTOSIS Apoptotic cells Normal
cells
Slide 10
1mm 2 Counting cells using Trypan Blue Harvest cells Re-suspend
cells in fresh medium Take 25l of cell suspension & Mix equal
volume of Trypan Blue Load the chamber with cell suspension (10l)
Count & Calculate avg number of cells Total number of cells
[cells/l] = Average number of cells counted/(counted area [mm sq.]
chamber depth [mm] dilution factor) Ex: Mix 100 l cells with 100 l
Tryphan Blue and inject 10 l under the coverslide Count all live
cells in 3 squares and get the avg no of cells. Square area:1mm 2
Chamber depth: 0,1 mm Dilution factor: First calculate the number
of cells per square: total number/3 squares = avg number This give
an equation like: Avg cell count(1mm 2 0.1mm 1/2) = no. of cells /
l => no. of cells / ml
Slide 11
Calculation of cell densities using a Brker chamber 1 A-square
(9 A-squares in total) 1.Mix 20l Cell culture with 20l Trypan Blue.
2. Carefully pipette solution onto the chamber until it is filled
(~15l). 3. Count the mean number of cells per A-square (of at least
5 squares) 4. Calculate cell density: (Mean cell number per
A-square) * 2* 10.000 = Number of cells / ml
Slide 12
~0.1 x 10 6 cells on a glass slide Label Funnel Filter card
Glass slide Slide holder Cell suspension, 100 - 200 l 500 rpm
during 2 minutes Preparation of cells for microscopy
Slide 13
Staining of cells for microscopy 1.After cytospinning let glass
slides dry briefly (10-15 min) 2.Stain slides for 5 minutes in
May-Grunwald solution 3. Stain slides for 20 minutes in Giemsa
solution 4. Wash slides 3 X 5 minutes in water 5. Let slides dry,
thereafter they are ready for observation in your light microscope
(x40 magnification) in Cytosol (May-Grunwald) Nucleus (Giemsa)
Slide 14
Apoptotic cell Healthy cell How do they look like?!