Page 22 - Laboratory manual for students FAR222 2019 20

FAR 222 Dosage Form II Laboratory Manual

6 STERILITY TEST

This is a practical to test on your ability to conform to Standard Aseptic Technique procedures.
There is NO NEED to submit a written report for this practical class. Discard all USED
syringes/needles and broken ampoules into the YELOW BIOHAZARD BINS.

Before you proceed, wipe your working area with alcohol. Make sure that the BUNSEN
BURNER IS SWITCHED OFF while you are swabbing the working bench with alcohol.

Each student will be supplied with:
1 vial
1 ampoule
1 tube of unknown sample
8 sterile test tubes
3 plate agar

EXPERIMENT 1: Sterility Test for Vial Sample
1. For this experiment, you are given: 4 sterile test tubes, 1 plate agar and 1 syringe with
needle.
2. Using a sterile pipette, aseptically dispense 5 mL of nutrient broth to each of the test tube.
Label the tubes as No.1, 2, 3 and 4.
3. Using a forceps, remove the aluminium lid from the vial.
4. Swab the rubber cap of your vial with alcohol.
5. Invert the vial and using a sterile syringe/needle, draw out 5 mL of the vial’s content.
6. Transfer this drawn-out sample to test tube No 1 (as illustrated in the picture below). Mix
gently.
7. Using a sterile pipette, transfer 5 mL of the broth/sample mixture from test tube No. 1 to
test tube No. 2. Repeat the dilution for test tube No. 3 and No. 4.
8. Take an agar plate and divide the plate into 4 sectors, mark each quadrant as 1, 2, 3 and
4.
9. Using a sterile wire loop, take a loopful of the dilution and streak on each quadrant
correspondingly (i.e. Quadrant No. 1 for sample from test tube No. 1, etc.)
10. Incubate your sample at 37°C, overnight (this includes all the serial dilution test tubes and
your inoculated plate agar).

5 mL
5 mL 5 mL 5 mL

1 2 3 4

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