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10.3 |
Colour
10.3 .1 Apparatus
10.3.1.1 A lovibond tintometer
with a GO watt standardized light source
10.3.1.2 A white porcelain tray
10.0.3.2 Procedure The instrument
shall be installed in an upright position. Put about
4 g of the sample in the white porcelain tray which
is held by a magnet and a spring behind the sample
aperture in the back plate of the white light cabinet.
A magnesium carbonate: block shall be similarly
placed on the outside of the other aperture. Having
placed the sample in position so that it can be
seen by reflected light in left hand field of the
viewing tube, the colour slides are shifted to the
right, adjusting the red; yellow and blue in correct
proportion until a perfect colour match is obtained.
The value of the slides effective in the instrument
is recorded. |
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10.4 |
Salmonella and
coliform
10.4.1 Apparatus
10.4.1.1 Incubator
10.4.1.2 Petri dishes
10.4.1.3 Test tubes
10.4.1.4 Blender
10.4.1.5 phi meter
10.4.1.6 Pipette
10.4.1.7 Loop and needle
10.4.1.8 Autoclave
10.4.1.9 Weighing balance
10.4.2 Broth and reagents
10.4.2.1 Lactose broth
10.4.2.2 Tergitol anionic 7
10.4.2.3.Teltrathionate brilliant green
broth
10.4.2.4 Selenite cystine broth
10.4.2.5 Brilliant green sulfadiazine
agar
10.4.2.6 Salmonella shigella agar
10.4.2.7 Bismuth sulphite agar
10.4.2.8 Triple sugar iron agar
10.4.2.9 Lysine iron agar
10.4.2.10 Violet red bile agar or desoxy
cholate agar
10.4.2.11 Imole/dm3 of sodium hydroxide
solution of hyfrochloric acid
10.4.3 Analysis of Salmonella |
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10.4.3.1 |
Weigh accurately
about 50 g of sample and blend in a blender with
450 cm of lactose broth for 1 minute. Adjust the
01 to 6.8 + 0.2 by adding 1 mole/dim 3 of sedium
hydroxide solution or 1 mole/dm3 of hydrochloric
acid. |
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10.4.3.2 |
Add 2.7 5 cm 3
of tergitol anionic 7 and finely grind in a blender
for 2 minutes, the lit shall be slightly opened.
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10.4.3.3 |
Incubate the mixture
at 35'-- 37 'C for 48 + 3 hours. |
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10.4.3.4 |
Prepare 2 test
tubes with screw stoppers, one containing 10 cm3
of terathionate brilliant green broth and the other
containing ,l0 cm3 of. selenite cystine broth. Pipette
one at a time 1 cm 3 of incubated sample and put
into each test tube, then .further incubate those
2 test tubes for 24 ± 2 hours. |
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10.4.3.5 |
After the incubation,
streak a loopful of terathionate brilliant green
broth on each petri dish of dry brilliant green
sulfadiazine agar, salmonella shigella agar and
bismuth sulphite agar in a manner to obtain well
isolated colonies, streaking for three times on
each agar. Repeat the above process with selenite
cystine broth. |
