an investigation into the antibacterial activities of medicinal plants ...

Twofold serial dilutions were made from row (B) to row (G) to obtain dilutions
ranging from 1:2 to 1:64.
50 µl bacterial broth suspensions (10 6 – 10 8 cfu/ml) were than added to each
of the microtitre plate wells.
Bacterial growth control and sterility controls were included.
Bacterial control well contained only water and bacterial suspension.
All solvents including extracts, traditional preparations, diluents, growth
medium were subjected to sterility assessment in microtitre plates and
cultured on blood-agar plates.
All extracts and traditional preparations (decoctions & infusions) were tested in
triplicate in the microtitre plates and test performed three times.
Covered microtitre plates placed in a closed, moist container were incubated
overnight shaking (140 rpm) at 37 o C.
Columns (1-3)
Columns (4-6)
Columns (7-9)
Columns (10-12)
Triplicate
Triplicate
Triplicate
Sterility Controls
Rows A Undiluted extract
B
C
D
E
F
G
H
FIGURE 4
1:2 extract dilution
1:4 extract dilution
1:8 extract dilution
1:16 extract dilution
1:32 extract dilution
1:64 extract dilution
ORGANISM
CONTROLS
Microtitre plates contained 50 µl of:
Distilled H 2 O
Extract
Bacterial broth
INT solution
Layout of the 96-well microtitre plate: dimensions and test suspensions
DAY 2 – Reading of microtitre plates
First reading - turbidity reading of microtitre plates read at 550 nm with the
microtitre plate reader (ELX 800 – Biotek) while ensuring no moisture or
fingerprints on microtitre plate reading surface.
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