4 screening – Hach-Lange LUMISTOX 300 LPV321 User Manual User Manual
Page 12

LUMIStox 300 Operating Manual
Dr. Bruno Lange GmbH
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Page: 12
2.4 Screening
Screening is the simpliest way of determining the toxicity of a sample. The result is
expressed as the percentage inhibition of the luminescence in the test solutions relative
to a control solution. With a LUMIStherm, double determinations of 9 samples or single
determinations of 14 samples can be carried out in one sequence.
Work steps:
1.
Prepare sample(s).
2.
Pipette 1.5 ml (for double determinations) or 1 ml (for single determinations) into
each measuring cuvette and bring to the correct temperature in the LUMIStherm.
3.
Bring 1.5 ml or 1 ml of the control solution (2% NaCl solution) to the correct
temperature in position A1 of the LUMIStherm.
4.
Reactivate the preserved bacteria by following the instructions in the package
circular.
5.
Pipette 0.5 ml bacteria suspension into measuring cuvettes.
6.
Quickly add 0.5 ml control solution or sample to the bacteria suspensions.
7.
Wait for the incubation period, e.g. 5, 15 or 30 minutes, to elapse.
8.
Select evaluation mode
9.
Measure the control and test solutions and record or print the results.