Clarification of meat suspensions using column filtration and rapid quantification of viable microbial cells using flow cytometry

A simple column filtration was developed to clarify meat homogenate suitable enough to quantify and assess the viability of bacterial population using flow cytometry. The removal of debris from homogenized meat suspensions was achieved by passing through different column materials such as sand particles, glass beads, dowex resin, and cell debris remover (CDR). Total plate counts on tryptic soy agar and lactic acid bacteria counts on MRS agar were done on the clarified suspensions. Absorbance of the clarified suspensions was measured at 600 nm. Among the material compared, sand and glass beads gave more than 90% recovery of bacterial cells. The absorption spectra of the filtered suspensions were considerably less and the best results were obtained with CDR followed by dowex resin. BacLight viability kit was successfully used to stain the bacterial cells in the meat suspensions. Injured sub populations of E. coli in pure culture were also studied using this stain.