OXFAM-DELAGUA Water Testing Kit — Users Manual
19
3.3 Preparation of Culture Medium in the Field
You will need the following items:
1.
38.1g of Membrane Lauryl Sulphate Broth (MLSB)
(a)
2.
Distilled, or clean water
(b)
3.
10, polypropylene bottles (60ml)
4.
Measuring cylinder or graduated beaker
5.
Portable steriliser
(c)
or pressure cooker or cooking pot or pan
(a) The medium is available in 38.1g, pre-weighed amounts from Delagua Water
Testing Ltd
(b) See Appendix E for suggested alternative sources of water
(c) A portable steriliser kit is available from Delagua Water Testing Ltd
Method
1.
Carefully wash the plastic polypropylene bottles in clean, warm water before
use. If necessary, use a little detergent and then rinse well with clean water to
remove all traces of the detergent.
2.
Use distilled water if possible. If this is not available obtain the cleanest water
possible. DO NOT use water that has been treated with chlorine or any other
chemical disinfectant.
3.
Use the comparator and phenol red tablets in the kit to check that the pH of the
water is between 7.0 and 7.8. If it is not, it will be necessary to find an
alternative source of water.
4.
Measure out 500ml of clean water in a beaker.
5.
Add 38.1g of the MLSB powder to the 500ml of water in the beaker.
Mix to dissolve the powder completely. Apply gentle heat if the powder is
slow to dissolve. The culture medium will be clear with a bright red colour
when dissolved.
6.
Pour a suitable volume of culture medium (approximately 50ml, but no less
than 40ml) into each of the 10 polypropylene bottles. This is sufficient
medium in each bottle to carry out 16 tests; the maximum that can be
performed in one day using the Delagua kit.
7.
Replace the screw caps on the polypropylene bottles. Make sure the caps are
secure but do not tighten. Leaving the caps slightly loose prevents the bottles
from collapsing during sterilisation.
8.
If a pressure cooker is available, sterilise the culture medium as described in
Section 3.2, paragraph 7.
9.
If a pressure cooker or portable steriliser is not available, the medium can be
sterilised using a process called Tyndellisation. Note, this
Summary of Contents for OXFAM-DELAGUA
Page 3: ...OXFAM DELAGUA Water Testing Kit Users Manual 2...
Page 5: ...OXFAM DELAGUA Water Testing Kit Users Manual 4...
Page 7: ...OXFAM DELAGUA Water Testing Kit Users Manual 6...
Page 52: ...OXFAM DELAGUA Water Testing Kit Users Manual 51 7 2 Fault Finding Chart...
Page 56: ...OXFAM DELAGUA Water Testing Kit Users Manual 55 APPENDICES...
Page 61: ...OXFAM DELAGUA Water Testing Kit Users Manual 60 Appendix D Daily report sheet...
