Download Mouvement et division cellulaire

Is life one and undivided ?
-Is cellular division common to
all living beings ?
-Do divisions proceed in the
same way?
Is cellular division
common to all living
beings ?
It is thought that there is a
division of cells in all living
beings responsible the unity
of life :
For that we have counted the
number of animal, vegetable
and bacterial cells there are
before and after setting them
in a culture.
Material and methods
- optical Microscope and the cell of
Malassez allows us to observe
unicellular animal cells: vegetable
yeasts and cells
- Spectrophotometer and absorbance
(bacterial cells too small to be seen
with the optical microscope=>indirect
technical use)
- MTT colorimetry test on the plate
reader and (use for pluricellular
Optical microscope and
counting of the cells on a
Malassez slide
Preparation of the nutrient
necessary to yeast
Starch is the nutrient necessary to the
development of yeast. We want to know what the
concentration is for an optimal developement.
Dilution
1/10
1/10
1/10
Culture of yeasts
Incubation of yeast in the
previous tubes of culture The
tubes are then left in an
incubator for 24 Hours
Incubator
The incubator
makes it
possible to
maintain the
cells moving at
the right
temperature
needed for
their survival
Results
A t0
(en cell/mL)
At24
(en cell/mL)
Cell
multiplication
factor
water+yeast
water+yeast
water+yeast
Without
starch
Starch
0,0001g/ml
Starch
0,001g/ml
water+yeast
starch
0,01g/ml
6,00E+07
3,10E+07
3,30E+07
3,60E+07
2,10E+08
1,20E+08
1,7E+08
3,00E+08
3.5
3.9
5.2
8.3
The richer the culture medium is, the higher is the multiplicatio
of cells
Bacteria
1) Comparison of the growth of
bacteria in rich or poor
culture medium
2) Analysis with a
spectrophotometer
3) Absorbance 60 times higher in
a rich culture medium
Conclusion: need for a culture
medium rich in nutrients is
The spectrophotometer
and absorbance
The absorbance of
the solution is measured
with a laser.
This absorbance is
proportional to the cell
concentration of the
sample
Analysis of animal cells multiplication
using colorimetric test
Principle : Study of 2 culture mediums, one rich in nutrients in
presence of FCS (fœtal calf serum) and one poor in nutrients.
Colorimetric test:Test based on the activity of the protein MTT:
coloration by MTT increases with cell concentration.
1/Wavelenght 620nm. The absorbance is proportional to the cell
concentration
2/Tracing of the calibration line
3/Measurement of the absorbance of the different cell culture
concentrations from the calibration line .
Calibriing well
6 wells containing the rich
medium
6 wells containing the poor
medium
Colorimetric test example
Animal cells : colorimetric test
y = 535678x - 19893
R2 = 0,9691
6,00E+05
nombre de cellules
5,00E+05
4,00E+05
3,00E+05
2,00E+05
1,00E+05
0,00E+00
0
0,2
0,4
0,6
absorbance
0,8
1
The animal cells
Sample 1
Sample 2
Sample 3
Standart
Deviation
Average
+ FCS*
121525
127954
152056
133845
16095
+FCS
153663
45992
149381
116345
60965
-FCS
118311
53493
84028
85277
32427
-FCS
99027
60458
82421
80635
19346
2,E+05
2,E+05
•Foetal
•Serum
1,E+05
Cell number
•Calf
2,E+05
1,E+05
1,E+05
8,E+04
6,E+04
4,E+04
2,E+04
0,E+00
+ FCS
+FCS
-FCS
-FCS
The
number of
cells
decreases
in poor
culture
medium
Conclusion
1/Presence of a cellular division
in all living beings
2/Division in all living beings
requires nutrients