Principle: microorganisms are transferred from one medium to another by subculturing.
microbes must be transferred from one vessel to another or from stock cultures to various media for maintenance and study called subculturing and must be carried out aseptically. Microbes are alwasys present in the air and on lab surfaces, benches, and eqquipment--a source of contamination and interfere with experimental results unless proper aseptic techniques are used during subculturing figure (1). 1. Label the tube with name of organism and your initials. 2. hold the stock culture tube and the tube to be incoulated in the palm of your hand, secure with our thumb, and separae the two tubes to form a V in your hand. 3. Sterlize an inoculation needle or loop by holding it in the hottest portion of the Bunsen burner flame, until the wire becomes red hot.. Then, rapidly pass the upp portion of thehandle through the flame. Once flamed, the loop is never put down but is held in the hand and allowed to cool for 10 to 20 seconds. 4. Uncap the tubes by grasping the first cap with your little finger and the second cap with your next finger and lifting the clsure upward (never place down on bench). 5. After removing the closure, flame the necks of the tubes by briefly passing them through the flame. The sterile tranfer instrucment is further cooled by touching it to the stierile inside wall of the culture tube before removeing a small sample of the inoculum. 6. Use a loop or needle for removal of inoculum. do not gouge the agar.a needle is always used when transferring microorganisms to an agar deep tube broh solid andliquid cultures.A. for slant-to- broth, lightly shake the loop or needle in the broth culture to dislodge the microorganisms. B. for broth-to-slant transfer, obtain a loopful of broth and place at the base of an agar slant medium. lightly draw the loop over the hardened surface in a straght or zigzag line, from the base of the agar slant to the top. C. slant-to-agar-deep transfer, obtain the inoculum from the agar slant. insert a straight needle to the bottom of the tube in a straight line and rapidly withdraw along the line of insertion. this is called a stab inoculation. 7. Following incoulaiton, remove the instrument and reflae the necks of the tubes. 8. replace the caps on the same tubes from which they were removed. 9. reflame the loop or needle to destroy any remaining organsms. in this experiment you will master aseptic transfer.