Sunday, July 19, 2009

Agar Substitutes

Agar is one of those staples of the tissue culture industry we generally can not do without. Agar is a gelatin like substance which is derived from common seaweed. You can find it used in many old fashion and modern desserts such as those found in Japan and are known as anmitsu.

Agar has traditionally been employed universally throughout the world as a medium by which cultures of bacteria or fungus could be readily grown. Usually this product is sold in bulk quantities as a powder and mixed with water for use as it is required. Although agar is the product of choice there are always active amateur scientists that are looking for alternate items to use. I personally have used common grocery store purchased unflavored gelatin as a suitable substitute for agar. It worked very well and I was able to culture quite a variety of plants from it.

Several years back I heard of an individual who did some work on the use of sand in place of actual agar. Naturally I had to try this method out and also found that it too worked as expected.

The procedure for using the sand is to start with the type of sand that is generally employed for a child’s sand box. It is frequently referred to as play sand. Prior to using the sand in any sort of tissue culture protocol you should wash it well to remove any visible contaminates. Next place approximately one ounce of the sand into each of your culture flasks or baby food jars if you are using them for your cultures. Seal the top of the jars with a strip of aluminum foil and place it on a cookie sheet. Your oven should be set for 350 degrees and you should let the jars remain in it for at least one hour.

The jars should be cooled and approximately 30 ml of sterilized medium should be added at this time. The key is to add enough of the medium to saturate the sand but not so much that you cause your explants to float around. Finally you will want to aseptically close your jar with a sterilized lid. I boiled mine and then place them in the oven for a period of time in order to kill off any contaminates.

During the course of your tissue culture experiments if the culture starts to dry out you should then add some additional sterile medium to the container. Naturally you will want to add other items such as nutrients, etc to help with the explants growth. You should at this stage of the game use the sand as if it were the actual agar. If you would normally add a specific ingredient to your agar then add it to the sand.

You should have no problems using the sand in place of the agar and I personally have seen some very interesting results while using it.

Copyright @ 2009 Joseph Parish