SYNCHRONOUS GROWTH

 SYNCHRONOUS GROWTH

• Synchronous or Synchronized culture is a microbiological culture or a cell culture that contains cells that are all in the same growth stage.
• Synchronous growth helps studying particular stages or the cell division cycle and their interrelations.
• A Synchronous culture can be obtained either by manipulating environmental conditions such as by repeatedly changing the temperature or by adding fresh nutrients to cultures as soon as they enter the Stationary phase, or by physical separation of cells by Centrifugation or Filtration.
• An excellent and most widely used method to obtain synchronous cultures is the Helmstetter-Cummings Technique in which an unsynchronized bacterial culture is filtered through Cellulose nitrate membrane filter.
• The loosely bound bacterial cells are washed from the filter, leaving some cells tightly associated with the filter. The filter is now inverted and fresh medium is allowed to flow through it. New bacterial cells, that are produced by cell division and are not lightly associated with the filter, are washed into the effluent. Hence, all cells in the effluent are newly formed and are, therefore at the same stage of growth and division cycle. The effluent thus represents a synchronous culture.