Experiment

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EXPERIMENT 5

NAME

: SHABITA DEVI BHATTACHARYYA

INTAKE

: AUGUST 2016

LECTURER’S NAME

:MR MOHD NOOR

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PRACTICAL 5

TITLE: ASEPTIC TECHNIQUES AND TRANSFER OF MICROORGANISMS

OBJECTIVES

1. To explain and carry out proper aseptic techniques
2. To practice correct method of transferring microorganisms
3. To determine and carry out proper techniques of obtaining pure culture

APPARATUS

Bunsen burner, inoculating loop

MATERIALS

70% alcohol, broth culture, plate culture, sterile broth, petri plate with nutrient agar

PROCEDURE

A) TRANSFERRING THE INOCULUMS INTO DIFFERENT MEDIA

1. The lid of the culture was slightly lifted and a small amount of the organisms was scrapped off and the lid was closed
2. The sterile tube containing medium was picked up and the cap was removed with the little finger of the loop hand ( the edge of the lid was lifted just enough to insert the loop) *The cap was not set down
3. The lip of the tube was briefly flammed
4. The loopful of inoculums was placed into the medium in the respective tube, and the loop was withdrawed. ( The loop was streaked across the surface of the agar medium)
5. The lip of the tube was flammed again before replacing the cap. (the loop was removed and the lid was closed)
6. The inoculated tube was incubated at 37’C for 24 hour. ( the plates was in upside down position)
7. The loop was resterilized by placing it in the flame until it is orange

B) OBTAINING PURE CULTURE

1. The inoculating loop was sterilized
2. The lid of the culture plate was slightly lifted and a small amount of the organisms was scrapped                       off and the lid was closed
3. The edge of the lid was lifted just enough to insert the loop
4. The loop of across the surface of the agar medium was streaked using the pattern shown
5. The loop was removed and the lid was closed. The inoculating loop was resterilized
6. The streaked petri plate was incubated at 37’C for 24 hours
7. The isolated colonies of microorganisms growing on a streak plate was picked off and was transfered aseptically to sterile media to obtain pure cultures

DISCUSSION

       A pure culture is a culture that contains only one type of species organism. A pure culture is usually derived from a mixed culture (one containing many species) by transferring a small sample into new, sterile growth medium in such a manner as to disperse the individual cells across the medium surface or by thinning the sample many fold before inoculating the new medium. Both methods separate the individual cells so that, when they multiply, each will form a discrete colony.

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