Page 11
Copyright Wet Paper Publications 2010
Procedure
Step 1 Hold the bottle securely and drill three 3 mm holes in
the cap (Figure 11.2).
Step 2 Unscrew the plastic cap and remove any drill shavings.
Step 3 Sterilise the bottle, tube, golf tee and lid. A simple
method is outlined in the box below.
Step 4 Fit the inlet filter and outlet filter in two of the holes.
Step 5 Cut a piece of tube 3 cm long and place it through the
third hole.
Step 6 Place the sterile tee in this ‘access port’ to seal it.
Step 7 Now insert the air filter from Project 1.2 as should in
Figure 11.1.
Discussion
1. Explain why the container should be made from clear
transparent material.
2. Discuss the advantages and disadvantages of glass and
plastic containers.
3. List some containers that are readily available at low or no
cost.
4. Discuss the advantages of having an access port.
5. List some procedures that could be used to stop infection
through the access port.
Sterilizing
A simple method of sterilization is to use
household bleach.
• Follow the instructions on the bottle
for nappies - dilution is usually 1/5
dilution
• Fill a large tub of known volume with
water and use one part bleach to five
parts water
• Immerse all equipment to be sterilized
for one hour
- be careful of your clothing with
bleach as it can leave nasty white
marks on new jeans!!
Figure 11.1 Finished algal growth container
Figure 11.2 Step 1: Hold the bottle securely and drill three 3 mm
holes in the cap
Mick O'Connor
Mick O'Connor
1,2,3 5,6,7,8,9,10