Methods and kits for separation, concentration and analysis of cells

摘要

Processes are provided for removal of cells as cell pellets from liquid milk samples, or from cultures or extracts of other food materials or other materials of biological origin. The concentrated cells in the pellet can be analyzed by various techniques to determine the relative cell count, such as by lysing of the cells followed by measurement of ATP. Nucleic amplification, as by the polymerase chain reaction method, can be carried out using the cellular pellet directly, without need for isolation of nucleic acid from the cells. After the amplification, an assay can be carried out for amplified nucleic acid segment indicative of the presence of cells of interest in the sample. The invention thus provides methods for obtaining cellular components from samples of milk, and cultures or extracts of other materials, including food materials, and for determining relative contamination of milk and such other materials by microorganisms. The invention also provides kits for carrying out its various methods.