Fluorophos ALP
Fluorophos ALP Test Procedure

The Fluorophos ALP (Alkaline Phosphatase) test is used as an indicator of correct pasteurisation and the presumed safety of milk and dairy products.

  • ALP is DEACTIVATED at ~63ºC. Pathogens are destroyed at ~60ºC
  • ALP activity decreased → temperature/time condition to kill pathogens has been reached
  • ALP activity in RAW MILK ~ 400,000 mU/l → ALP activity in pasteurised milk 10-40 mU/l

The Fluorophos principle of measuring for residual ALP in pasteurised dairy products is by adding the test sample to a non fluorescent substrate. Any ALP present produces a FLUORESCENT compound and measuring this change in fluorescence is directly proportional to the concentration of ALP in the sample.


Substrate Preparation
When the Fluorophos is switched on allow 2 hours before use to ensure complete electronic stabilization.
1/ Pour the entire contents of one of the substrate buffer bottle into one of the powdered Fluorophos substrate bottle.

2/ Mix by gentle inversion for 3 minutes, to dissolve all of the substrate. Allow to stand for 15 minutes.

3/ Note date of mixing on bottle. The shelf life will be 60 days, stored at 2 – 6oC. To check the substrate warm 2 ml and place in Fluorophos. Run A/D Test (In Setup). Stabilized result should be less than 1200 (If over, replace substrate). If degrading quickly, contact QCL for advice.

Test Procedure
1/ Dispense 2ml of prepared Fluorophos substrate into a sufficient number of cuvettes for the proposed tests.

2/ Place substrate cuvettes in the block heater for a minimum of 10 minutes.

3/ Select product to be tested from the Fluorophos menu. Press TEST, ENTER, pick channel, ENTER, enter ID number if necessary, ENTER.

4/ Pipette 75ul of the milk/cream sample, into a pre-warmed substrate cuvette (see Pipetting Guide for more details).

5/ Press ‘TEST’ and select the ‘ALP Dairy’ menu.

6/ Scroll through the menu and press ‘Enter’ when the product to be tested is displayed.

7/ Pipette 75ul of the milk/cream sample, into a pre-warmed substrate cuvette.

8/ Mix immediately then insert the cuvette in the Fluorophos, within 20 seconds, and press ‘START’ to measure the sample.

9/ The sample is conditioned/heated for 60 seconds. 10/ After a further 2 minutes the result is presented in mU/L.

Test Sheets
Example Daily QC Sheet
QC Test Expected Result Actual Result Pass/Fail
A/D 302 blank 302 +/- 4 305 Pass
A/D 602 Daily Control 602 +/- 12 608 Pass
A/D Substrate <1200 897 Pass
Daily Positive Control Approx 500 mU/l 672 mU/l Pass
Printable Version
Example Test Sheet
Sample ID No Result mU/l   Sample ID No. Result mU/l
432423 <10      
453211 24      
564322 21      
442222 <10      
Printable Version