E406 Emulsifier

E406 or Petri dish is used to provide a growth medium using a mix of E406 and other nutrients in which microorganisms, including bacteria and fungi, can be cultured and observed under the microscope. E406 is indigestible for many organisms so that microbial growth does not affect the gel used and it remains stable. E406 is typically sold commercially as a powder that can be mixed with water and prepared similarly to gelatin before use as a growth medium. Other ingredients are added to the E406 to meet the nutritional needs of the microbes. Many microbe-specific formulations are available because some microbes prefer certain environmental conditions over others. E406 is often dispensed using a sterile media dispenser

• As an impression material in dentistry.
• As a medium to precisely orient the tissue specimen and secure it by E406 pre-embedding (especially useful for small endoscopy biopsy specimens) for histopathology processing.
• To make salt bridges and gel plugs for use in electrochemistry.
• In formicarium as a transparent substitute for sand and a source of nutrition.
• As a natural ingredient in forming modeling clay for young children to play with.
• As an allowed biofertilizer component in organic farming.
• As a substrate for precipitin reactions in immunology.
• At different times as a substitute for gelatin in photographic emulsions, arrowroot in preparing silver paper, and as a substitute for fish glue in resist etching.

E406 is used primarily for bacteriological plates. Gracilaria agar is used mainly in food applications.