An alternative method for the analysis of poly-beta-hydroxybutyrate (PHB) in microbial biomass based on FTIR spectroscopy was developed in which a semi-transparent, thin pellet of biomass was made with KBr and scanned by IR spectroscopy, from 400 cm(-1) to 2000 cm(-1). The IR spectra of the target biomass showed a distinct absorbance band of the carboxylic ester group at 1724.03 cm(-1). The technique can be used to screen large numbers of microorganisms for PHB production.