3. Results and discussion
The checkerboard assay is probably the most convenient way of assessing the antibacterial potential of plant extracts, chromatographic fractions or isolated compounds. In this method, the test extracts or compounds are able to diffuse more easily into the media. This method also gives the opportunity to determine an approximate MIC indicating the degree of potential antimicrobial activity compared with that of positive control, ciprofloxacin. The viability counts have to be determined ideally for each batch of bacteria used to enable an accurate calculation of colonies to be made.