The Process of Inoculation and Isolation

• Inoculation - the process of introducing microorganism onto a medium; the process involved in the production of an individual colony resulting from the exponential multiplication of a single cell
• Liquid specimens may be handled by using:

  Spread Plate Technique

  Pour Plate Technique

  Drop/spot Plate Technique
• Spread plate technique - spreading an amount of the specimen on the agar surface using a bent glass rod
• Pour plate technique - pouring and proper mixing of a fixed amount with the liquid agar (70°C)
• Drop/spot plate technique - delivering individual amount of 25 microliters onto agar such as when making dilutions (Miles Miara plate count)
• Solid materials - like food particles require maceration and suspending the particles in fluid. Isolation can then be done
• Sampling from the surface of objects - entails the use of sterile cotton swabs
• Swabs - are wet with sterile broth to enhance the adhesion of surface materials
• The swab containing the sample - will be used to inoculate one end of an agar plate
• After the swab is put back into the broth, the broth may then serve as transport media or reference/stock material.
• Streaking - a method of isolating individual microorganism growing on an agar surface; done with the use of a sterile wire loop
• The wire loop is sterilized after every streak made
• streak 1,2,3,4 - there is a decrease in the number of microorganisms isolated