5. Material for test
Culture for patient sample
Test tube rack
Slain solution 0.45% PH 4.5-7
Dispenser
stick swab
DensiCHEK plus instrument To measure microorganism
density
Tube fixed pipetting (red for gram -ve and blue for gram +ve)
Vortex
Tissue
Pastuer pipette
Powder free gloves
Biohazard container
6. Sample Preparation
Bacterial suspensions prepared.
A sterile swab is used to transfer
a sufficient number of colonies (3)
of a pure culture and to suspend the
microorganism in 3.0 mL of sterile
saline (0.45% NaCl) in a clear plastic
test tube.
Mix suspension use Vortex until
have homogenous suspension
7. Put the tube in DensiCHEKplus
then rotate 3600after that
instrument read density
acceptable range 0.5-0.63 for
bacteria and for yeast 1.8-2.2
The turbidity is adjusted
accordingly Table 1 and
measured by DensiChekTM.
If the turbidities is less than
range add more bacterial
coloney
If turbidity is more than range
add more saline 0.45%
To avoided contamination don't
add solution from dispenser
DensiCHEK™ Plus INSTRUMENT FOR
turbidity adjustment
8. ID and AST pair setup
Tube fixed pipetting (red for gram -ve and
blue for gram +ve) From suspension take
145mm for gram-ve bacteria and 280mm
from gram+ve or yeast Add the above
volume to 3 mm of saline
Vitek Tube Compact Cassette
• The test suspension tube is placed into
the “cassette”, with Reagent card
• Sealed test kits are moved into the
reader/incubator automatically.
• Test kits incubate and analyze
automatically.
10. There are currently four
reagent cards available for
the identification of different
organism classes as follows:
1. GN - Gram-negative
fermenting and non-
fermenting bacilli.
2. GP - Gram-positive cocci
and non-spore-forming
bacilli .
3. YST - yeasts and yeast-like
organisms.
4. BCL - Gram-positive
spore-forming bacilli.
