Agar-Making Protocol

Materials and Equipment Needed

  1. Agar powder
  2. Autoclaved deionized water
  3. Spatula
  4. Weight boat
  5. Digital scale
  6. Sterile autoclave-safe container
  7. Autoclave tape
  8. Pyrex dish
  9. Autoclave gloves
  10. Graduated cylinder

Safety Issues

Use caution when working with the autoclave.  Always wear autoclave gloves when handling hot materials out of the autoclave.  Also, use caution when opening the autoclave door after the process is completed, because the steam may cause burns.  Never open the autoclave door if psi is 0.4 or above.

Time Required

5-10 minutes for mixing agar.  Autoclave time depends on volume of liquid

Procedure

Step Image

Gather all the necessary equipment.
Weigh the appropriate amount of agar using a digital scale.  Zero out the weight of the weigh boat by pressing "zero" on the scale.

Dilution Rate of Agar

Amount of
agar (g)

Volume of
water (ml)

3.2

400

4.0

500

8.0

1000

  
Using the weight boat, pour agar into autoclave-safe jar.  Add appropriate amount of autoclaved deionized water (see table above for dilution rate of agar).  Seal the cap loosely on the jar and place autoclave tape on the cap.


Place agar mixture in a pyrex dish that is filled with 1 inch of water.
Autoclave the mixture.  (Refer to autoclave protocol for liquid and gravity runs for the appropriate procedure.)
 
Wearing autoclave gloves, remove the sterilized agar from the autoclave.
 
Tighten the cap on the bottle.  Turn it upside down and then right side up three times.  Loosen the cap to allow for steam escape.  Repeat this every 10 minutes until the agar bottle is comfortable to the touch.  This light mixing procedure is critical to preventing the agar from settling to the bottom and becoming lumpy.  Use as needed.