Dear Vikas Kumar,

First you can dry your extract after that you can dissolve it in the DSMO or any other suitable solvent. Than you can use it as per Clinical Laboratory Standard Institute Guidelines criteria (CLSI). 

Best Regards,

Dr Anand

 http://www.scielo.br/pdf/bjm/v38n2/v38n2a34.pdf

you may follow above article

Medicinal plant extracts journal. go on Google. you will find many journals and instructions for submission of an article on line. good luck

Evaluation of Antimicrobial Activity of the Methanol Extracts from 8 Traditional Medicinal Plants

Chang-Geun Kang,1 Dae-Sik Hah,2 Chung-Hui Kim,3 Young-Hwan Kim,4 Euikyung Kim,1 and Jong-Shu Kim 1

Abstract

The methanol extract of 12 medicinal plants were evaluated for its antibacterial activity against Gram-positive (5 strains) and Gram-negative bacteria (10 strains) by assay for minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) . The antibacterial activity was determined by an agar dilution method (according to the guidelines of Clinical and Laboratory Standard Institute) . All the compounds (12 extracts) of the 8 medicinal plants (leaf or root) were active against both Gram-negative and Gram-positive bacteria. Gram-negative showed a more potent action than Gram positive bacteria. The MIC concentrations were various ranged from 0.6 μg/ml to 5000 μg/ml. The lowest MIC (0.6 μg/ml) and MBC (1.22 μg/ml) values were obtained with extract on 4 and 3 of the 15 microorganisms tested, respectively.

Keywords: Antimicrobial activity, traditional medicinal plants, minimum inhibitory concentration (MIC) , minimum bacterial concentration (MBC) , methanol extract, agar dilution method .For more please read at following link.

Warm Regards

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3834511/

You can 59

It can be made 500 ug/ml of dried extract in methanol, and 200 ul of this can be loaded in filter paper disc and dried. This disc can be used for test. Several crude extract may not show zone of inhibition at this concentrations, then 1000 ug/ml concentration can be made.