image taken from: http://catalog.bd.com/bdCat/viewProduct.doCustomer?productNumber=446251

image taken from: http://www.bd.com/ds/productCenter/MD-AffirmVPIII.asp

hi everyone:) i have been in the microbiology laboratory for almost 3weeks and i have learnt quite a lot of things...now i would like to share with you one of the tests which i have found it quite interesting:)

The test is VP3 test. The full name is known as BD Affirm (Trademark) VPIII Microbial Identification Test. This test make use of DNA probe to detect and identify Candida species, Gardnerella vaginalis and Trichomonas vaginalis nucleic acid in vaginal fluid specimens from patients with symptoms of vaginitis (infection of the vagina).

Prinicple of the test:

-Based on nucleic acid hybridization where the complementary nucleic acid strands will align to form specific double stranded hybrids

This test uses 2 specific nucleic acid probes for each organism, a capture probe and a color development probe that are complementary to the genetic sequences of the target organism. The captured probe will be immobilized on a bed embedded in a Probe Analysis Card (PAC) that contains a seperate bead for each target organism. The colour development probes are contained in a multi-well Reagent Cassette (RC).

Sample Requirement: High Vaginal Swab

Method:

1)12 drops of lysis solution (0.4ml) were added to the sample and was swirled for 10 seconds

2)the sample was incubated for 10minutes (during this time, the lysis solution will rupture the walls of the cells of the organisms thus releasing the nucleic acid).

3)12drops of (0.6ml) of Buffer solution were added to the sample and the tube was flicked 10times before the cap was disposed (the buffer solution acts to stabilize the nucleic acid and establishes the stringency conditions needed for specific nucleic acid hybridization.)

4)4drops (0.1ml) of substrate solution was added to well 7

5)a filter tip was placed on the tube. the sample was dispensed entirely into well 1

6)PAC was placed into well 1

7)the automated processor was started

8)after about 32minutes,the PAC was removed and the results were interpreted

Results:

- +ve :any blue colour
- -ve : no colour

Contents in the wells:

Well no 1: patient's sample


Well no 2: Hybridization Solution


Well no 3: Wash solution


Well no 4 : Conjugate


Well no 5: wash solution


Well no 6: Wash solution


Well no 7: substrate buffer

i hope the pictures will make you understand more about the test:) have fun in SIP:)

For more information, you can also visit the website which i have taken the image from:) sorry i couldnt find any larger image:)

Rachael
0606168C
Tg01