Hach Eclox, User Manual

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sources of supply is contained in the quality certificate that comes with every box of
luminescent bacteria reagent.
The standard stock solutions should be prepared with 2% NaCl solution. The pH of
the sample should not be adjusted. Prepare the standard solution such that 0.5 mL
of standard solution and 0.5 mL of bacteria solution gives the above mentioned final
test concentration. Check in duplicate whether those standard tests give 20–80 %
inhibition after 30 minutes of exposure time at 15 °C.
10.4 Reagent storage and preservation
The freeze-dried reagent can be kept at -18 °C until the expiration date shown on
the package.
Tubes that contain thawed but not reactivated freeze-dried luminescent bacteria
can be frozen again and kept on stock.
The reagent can be transported or shipped up to 7 days at no more than 25 °C.
10.5 Prepare the reagent
Prepare the Luminescent Bacteria Toxicity Test reagent in the field using the
procedure in this section.
The amount of light made by the luminescent bacteria is affected by the
temperature at which the reagent is reconstituted. The luminescent bacteria and
reconstitution solution must be mixed as cold as possible at refrigerator
temperatures (3 to 8 °C). If the temperature is higher, the amount of initial light
made by the bacteria will be lower.
10.6 Prepare the stock suspension using the LCK491
reagent
Prepare the stock suspension by adding the reconstitution solution to the
freeze-fried bacteria reagent. The reconstitution solution rehydrates the bacteria
reagent.
Reconstitution solution is specially made non-toxic ultra pure water. Do not make
reconstitution solution or use substitutes.
The dry reagent can be kept at ambient temperatures (not higher than 25 °C) up to
5 days without cooling. Make sure that reactivation conditions are as cool as
possible.