Transcript 1087-Aseptic Technique Practical

Aseptic Technique
• This is how we grow bacteria and moulds
without contaminating our cultures or
ourselves.
• It is also called ‘sterile technique’.
• You must always read the ‘precautions
sheet’ before you start.
• And do everything it tells you to!
How to prepare
• Turn the petri dish upside down.
• Stick a label on the base, with the date,
your initials and the treatment written on it.
• Turn it back the right way up. Make sure
you do not open it by accident.
• Collect a bunsen burner, mat and goggles.
• Put on the goggles, light the bunsen.
Pouring the agar
• Loosen the screw cap of a sterile bottle of agar.
• Tilt the bottle slightly so that ..………….
………………………………………………
• Remove the cap and pass the neck of the bottle
through the top part of a blue flame a few times. This
will………………………………………
• Lift and hold the petri dish lid over the base and
quickly pour in the agar.
• Put the lid back and gently jiggle the dish to spread
the agar across the base. Leave it to set.
• Rinse the bottle under the tap. Place it with the cap
separate in the washing up tub.
Making a streak plate
• Heat an inoculating loop until it glows red.
• Let it cool and then pick up a little of the
culture on the loop.
• Lift the petri dish lid and zig-zag the loop
across the surface of the agar.
• Close the lid. Re-flame the loop to leave it
sterile.
What we did
• Now draw on the
outline what your dish
looked liked after you
added the soil streak.
• Remember we added
2 pieces of sticky
tape.
• Say why ……………
• ……………………….
Our results
• After incubating the
dishes at 25oC for two
days, the dish was
sealed.
• Our dish looked like
this >>>
• I estimate we had
grown …… colonies
of bacteria.
• What it looked like