MIC-01Foundation

Aseptic Technique & Bench Setup

Scenario brief

A new analyst has contaminated three plates this week. Set up a clean bench and demonstrate correct aseptic technique from loop sterilisation to plate sealing.

About 6 min
6 parts

Show & Teach

1 Watch every step done for you, with what it is and why it matters.

Guided Mode

2 Do every step yourself, with a coach that points the way and explains.

Solo Mode

3 No hints. Your own technique is marked, and earns stars, XP and Keys.

Three stars already. Play it again any time to keep your hand in; refresher rounds will bring it back before it fades.

Your way to doing this test unaided

1Watched it shown: not yet
Show & Teach, start to finish
2Did it with a coach: not yet
Guided Mode, every step yourself
✓Passed it alone: done
Solo Mode: 3 of 3 stars so far
✓Signed off here: done
Three stars alone: every step right, unprompted

Then, at a real bench: do it once with a trained colleague watching, following your own laboratory's procedure and limits. That observed run is what clears you to work unsupervised there.

Refresher due. A few quick questions will keep this skill sharp.

Refresh now

What you'll do

This is the procedure you'll follow at the bench. Open a part to read it step by step, with the reason for each step, before you start.

1
Collect your kit8 things to fetch
Fetch what the test needs from the stores around the lab, or have it brought to you.
The method for this part
What you check
- • 70% alcohol spray
- • Bunsen burner
- • Agar plates
- • Marker pen
- • Inoculating loop
- • Broth culture
- • Agar plate
- • Tape
What you decide by
- • Take only what the test uses: anything extra on the bench is clutter to reach over.
2
Pre-use checks1 instrument to check
Before you rely on anything, read its label and its record. Today's date matters.
The method for this part
What you check
- • Agar plates
- • Read its label, for each
- • Read its record, for each
What you decide by
- • Equipment that needs calibrating carries a label showing when it was done and when it is next due. Check 'Next due' against today's date.
- • Each record form prints its own acceptance limit. A reading outside it means the equipment is not fit for use.
- • Culture media are released batch by batch, after a sterility check and a growth check with a control strain.
- • Anything out of date or out of limits is taken out of service: labelled 'Do not use', reported, and not used until it is put right.
- • The limits and intervals here are set for this exercise. In your own laboratory, use the ones in its procedures.
What you can decide
Fit for use · Do not use: label it and report
3
Prepare the bench7 steps · 1 by hand
Get yourself and the bench ready before any culture is opened.
The method for this part
1. 1
  Tie back hair, remove rings and watch
  Tie back long hair and take off rings and your watch.
  Hair and jewellery carry microbes and can dangle into a culture or a flame.
2. 2
  Put on a buttoned lab coat
  Put on a clean lab coat and fasten it.
  A fastened coat protects you and keeps fibres off the bench.
3. 3
  Wash and dry your handsDone by hand, to every part of both hands
  Wash and dry your hands thoroughly.
  Hands are the commonest source of contamination.
4. 4
  Wipe the bench with 70% alcoholContact time: 30–120 s
  Spray and wipe the work area, then leave it wet for the contact time.
  Disinfectant needs contact time; wiping it straight off leaves survivors.
5. 5
  Light the Bunsen burner
  Once the alcohol has dried, light the burner and set a blue flame.
  Never light a flame near alcohol. The updraft helps keep dust off your work.
6. 6
  Lay out only what you need
  Plates, culture, loop and marker within reach; everything else away.
  Clutter means reaching over open cultures.
7. 7
  Label the plates on the base
  Write your name, the date and the organism on the base of each plate.
  Lids get swapped; the base stays with the agar.
What goes wrong here
- Label the plate lids. Lids can be swapped between plates: label the base.
- Spray alcohol near the lit burner. Alcohol vapour catches fire: disinfect before lighting the burner.
- Prop the plates open to air them. Open plates collect airborne microbes.
4
Streak a plate11 steps
Subculture the broth onto a plate to get single colonies.
The method for this part
1. 1
  Flame the loop red-hot
  Heat the wire from the handle end to the tip until it all glows red.
  Heating base to tip burns material off gradually instead of spattering it.
2. 2
  Let the loop coolCooling: 5–20 s
  Hold it still near the flame for about 10 seconds.
  A hot loop kills the cells you pick up and makes the culture spit.
3. 3
  Remove the cap with your little finger
  Grip the cap with the little finger of your loop hand; don't put it down.
  A cap on the bench picks up contamination.
4. 4
  Flame the bottle neck
  Pass the neck of the bottle through the flame.
  It kills microbes on the rim and makes air flow outwards.
5. 5
  Take a loopful of culture
  Dip just the loop into the broth.
  A loopful is plenty; dipping the handle in would contaminate it.
6. 6
  Flame the neck and recap
  Flame the neck again and replace the cap.
  Close the bottle the way you opened it.
7. 7
  Lift the lid just a little
  Raise the lid at an angle, like a shield over the plate.
  Less exposed agar means less airborne contamination.
8. 8
  Streak the first quadrant
  Spread the inoculum across the first quarter of the plate.
  The first streak lays down most of the cells.
9. 9
  Flame, cool and streak quadrants 2–4
  Flame and cool between quadrants, dragging each from the last.
  Each pass dilutes the cells so single colonies grow at the end.
10. 10
  Close the lid and flame the loop
  Close the plate, then flame the loop before putting it down.
  Never put down a loop that still carries culture.
11. 11
  Tape with two strips, incubate inverted
  Secure the lid with two short strips and incubate upside down.
  Inverted plates keep condensation off the agar; the culture still needs air.
What goes wrong here
- Put the cap down on the bench. The inside of the cap touches the bench and contaminates the culture.
- Take the lid fully off. An open plate collects airborne microbes.
- Blow on the loop to cool it. Your breath is full of bacteria.
- Press the loop into the agar. Gouging the agar ruins the streak; glide over the surface.
5
Check your understanding3 questions
Answer the questions.
6
Clean up4 steps · 1 by hand
Leave the bench safe for the next person.
The method for this part
1. 1
  Turn off the burner
  Turn off the gas at the tap.
  Turn it off before using alcohol, and never leave a flame unattended.
2. 2
  Discard used items into the discard pot
  Put used pipettes and loops into disinfectant or the autoclave bag.
  Used items carry live culture until they're decontaminated.
3. 3
  Wipe the bench with 70% alcoholDone by hand, to the whole bench
  Disinfect the whole work area again.
  Kills anything spilt or splashed during the work.
4. 4
  Remove your coat and wash your hands
  Hang up your coat and wash your hands before leaving.
  Leaves the lab's microbes in the lab.
What goes wrong here
- Leave the burner on for the next person. An unattended flame is a fire risk.

What you'll take away

Disinfect the bench before lighting the burner: alcohol is flammable.
Flame the loop red-hot, base to tip, before and after every use.
Never put a cap or a loaded loop down on the bench.
Open lids only a little, as a shield; label the base of the plate.
Streak in quadrants, flaming between them, to get single colonies.

Equipment unlocked

Bunsen burner
Inoculating loop
Bench disinfectant