These kinds of bacterium carry mutations in genes involved in histidine synthesis, so that they require histidine for growth.(Without histidine they would not live)
We chose TA102 (a kind of Salmonella) to be tester, and handled with two negative controls and two positive controls.
The two negative controls are Water-TA102 and DMSO-TA102, and the positive controls are Mitomycin C (-S9) and 2-Anthramine (+S9)
Mitomycin C is a anti-tumor medicine and 2-Anthramine is a chemical compound that may cause cancer.
And here the S-9 fraction is a substance extracted from liver, it contains many kinds of enzymes. We use the S-9 fraction to stimulate the metabolism of a liver. Then we could know if the substance that a liver metabolized would be a mutagen.
S-9 fractions
After we mixed some histidine/biotin,TA102,mutagen with S-9 and without S-9 and top agar. We poured the mixture onto each MA plates separately. Then put all plates into an oven (37oC) for three days.
Finally, we have count out all the CFU(colony-forming unite) the calculate if the positive controls is two times or higher more than the negative controls, that we can assure if an agent is a mutagen.
Experimental Record
Group 3
|
Plate1 (CFU)
|
Plate2 (CFU)
|
Plate3 (CFU)
|
Average(CFU)
|
Water
|
98
|
105
|
107
|
103
|
DMSO
|
150
|
113
|
183
|
149
|
Mitomycin C
|
670
|
851
|
767
|
763
|
2-Anthramine
|
239
|
174
|
181
|
198
|
Analysis
Group 3
|
Ratio with water
|
Mutagen
|
Mitomycin C (solvent:water)
|
7.408
|
YES
|
2-Anthramine (solvent:DMSO)
|
1.329
|
NO
|
Data of Whole the Class
|
||||
G1
|
Average
|
|||
NC (-S9)
|
160
|
65
|
78
|
101
|
PC (-S9)
|
513
|
334
|
624
|
490.3
|
NC (+S9)
|
232
|
6
|
237
|
158.3
|
PC (+S9)
|
178
|
184
|
181
|
181
|
G2
|
||||
NC (-S9)
|
131
|
167
|
192
|
163.3
|
PC (-S9)
|
437
|
302
|
368
|
369
|
NC (+S9)
|
481
|
327
|
303
|
370.3
|
PC (+S9)
|
362
|
387
|
423
|
390.7
|
G3
|
||||
NC (-S9)
|
98
|
105
|
107
|
103.3
|
PC (-S9)
|
670
|
851
|
767
|
762.7
|
NC (+S9)
|
150
|
113
|
183
|
148.7
|
PC (+S9)
|
239
|
174
|
181
|
198
|
G4
|
||||
NC (-S9)
|
140
|
114
|
128
|
127.3
|
PC (-S9)
|
463
|
1340
|
463
|
755.3
|
NC (+S9)
|
116
|
96
|
158
|
123.3
|
PC (+S9)
|
108
|
154
|
262
|
174.7
|
G5
|
||||
NC (-S9)
|
212
|
210
|
225
|
215.7
|
PC (-S9)
|
800
|
488
|
495
|
594.3
|
NC (+S9)
|
157
|
159
|
176
|
164
|
PC (+S9)
|
155
|
153
|
200
|
169.3
|
G6
|
||||
NC (-S9)
|
103
|
139
|
139
|
127
|
PC (-S9)
|
344
|
330
|
331
|
335
|
NC (+S9)
|
188
|
180
|
179
|
182.3
|
PC (+S9)
|
104
|
190
|
197
|
163.7
|
G7
|
||||
NC (-S9)
|
21
|
17
|
140
|
59.3
|
PC (-S9)
|
420
|
320
|
108
|
282.7
|
NC (+S9)
|
109
|
151
|
156
|
138.7
|
PC (+S9)
|
96
|
158
|
176
|
143.3
|
G8
|
||||
NC (-S9)
|
80
|
87
|
51
|
72.7
|
PC (-S9)
|
802
|
720
|
832
|
784.7
|
NC (+S9)
|
238
|
253
|
261
|
250.7
|
PC (+S9)
|
350
|
387
|
189
|
308.7
|
Average of all eight groups
|
CFU(Average)
|
Water
|
121
|
DMSO
|
192
|
Mitomycin C (-S9)
|
547
|
2-Anthramine (+S9)
|
216
|
Ratio Matrix
Numerator
Denominator
|
Water
|
DMSO
|
Mitomycin C (-S9)
|
2-Anthramine (+S9)
|
Water
|
1.0000
|
1.5868
|
4.5207
|
1.7769
|
DMSO
|
0.6302
|
1.0000
|
2.8490
|
1.1250
|
Mitomycin C (-S9)
|
0.2212
|
0.3510
|
1.0000
|
0.3949
|
2-Anthramine (+S9)
|
0.5601
|
0.8889
|
2.5324
|
1.0000
|
(2.0000>VALUE>1.5000) (>2.0000)
Test Substance
|
Description
|
Water
|
To compare with other three substances,
it is not a mutagen.
|
DMSO
|
To compare with water, its effect is just
a little stronger, but not really a mutagen.
|
Mitomycin C(-S9)
|
To compare other three compounds, it is a
really strong mutagen.
|
2-Anthramine
|
To compare with water, it is almost to be
a mutagen, but its effect is just like DMSO. It is hard to decide that is
cause by DMSO, 2-Anthramine or the metabolites of S9 from 2-Anthramine.
|
No comments:
Post a Comment