This document outlines a procedure to test the quality of a milk sample using methylene blue dye. The procedure involves adding methylene blue dye drops to test tubes containing 10ml of milk sample. The test tubes are then incubated at 37°C for 15 minutes. The time it takes for the dye color to disappear indicates the quality of the milk sample - the faster the color disappears, the poorer the quality. The document was prepared by Amjad Khan Afridi and demonstrated the procedure on August 8, 2016.

1. 1
Amjad Khan Afridi 8th
August , 2016
Methylene Blue is an organic compound , in dark green or lustrous crystalline
powder, used in the treatment of methemoglobinema, as a strain
in pathology and bacteriology, and as a diagnostic aid in the detect ion of
premature rupture of fetal membranes.
Objective:
 To check microbial load in the milk sample.
 To check the quality of milk sample.
Requirements:
1. Milk sample
2. Methylene Blue dye
3. Test tubes
4. Test tubes holder
5. Test tubes stand
6. Water bath or incubator
7. Dropper or Pipettes and its tips
8. Swab cotton
9. Aluminum foil
Procedure:
A. Take test tubes and pour 10 ml of milk sample in each test tubes.
B. Then labeled the test tubes.
C. Then add drops ofMethylene Blue Dye in each test tubes.
D. Next incubate the test tubes at 37 C in water bath for 15 minutes.
E. Result: Absorb the color of the test tubes with respect to times.
F. If the color is changed its means that the milk sample having contamination (
Load of Microbes), and the quality of milk is not good, while if there is no
color changed in the test tubes, its means the quality of the concern milk
sample is good.

2. 2
Amjad Khan Afridi 8th
August , 2016
Interpretation:
 If dye color is disappear in 30 minuets , its means that the milk has very
bad ( Poor)quality.
 If dye color is disappear in 1 hour , its means that the milk has bad quality.
 If dye color is disappear in 6 hours , its means that the milk has fair quality.
 If dye color is disappear in 8 hours, its means that the milk has good quality.
 If dye color is disappear in 24 hours, its means that the milk having
excellent quality.
Demonstrated By Madam Sadira 8th
August , 2016
Prepared by Amjad Khan afridi, 7th
semester