More on Agar Tissue Culture
26 Jan 2021

More on Agar Tissue Culture

Anjali Singh, MS

As a content and community manager, I leverage my expertise in plant biotechnology, passion for tissue culture, and writing skills to create compelling articles, simplifying intricate scientific concepts, and address your inquiries. As a dedicated science communicator, I strive to spark curiosity and foster a love for science in my audience.

Anjali Singh, MS
Table of Contents

What is Agar?

Agar is a mixture of agarose and agaropectin, where agarose is a linear polysaccharide and agaropectin is a heterogenous sulfated galactan mixture. These are obtained from the outer layer of red algae (Rhodophytes) seaweeds that mainly include Gelidium and Gracilaria.

Agar is insoluble in cold water but it’s readily soluble in hot/boiling water. The dilute agar solution is liquid at 42 °C (108 °F) but solidifies at 37 °C (99 °F) into a firm gel. Also, the solidification of agar is pH-dependent i.e it solidifies in the pH range of 5.4-5.7. To increase the pH in this range, it is advisable to use a KOH solution. Moreover, it’s a must to autoclave the media (containing agar) for sterilization.

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How Commercial Agar is prepared? 

The outer layers of Gelidium and Gracilaria are held in 0.2% sulfuric acid overnight to extract the agar and then sodium hyposulfite is added for bleaching. After extraction, the liquid extract is filtered and cooled. This procedure leads to the gelling of agar, which is cut into several suitable pieces. These pieces are then frozen and thawed to liberate water and other impurities from agar. The liberated water and impurities are discarded and the residual agar is sundried.

Agar undergoes several other purification steps to be sold as research-grade commercial agar. These steps include washing with water and alcohol, filtration, freezing-thawing, electrodialysis, and precipitation by alcohol.

Applications of Agar

Agar has many applications, out of which some are explained below:

  • It’s used in canning meat, fishes, and poultry.
  • It’s used in medicine, cosmetics, and dentistry.
  • It’s used as a clarifying agent in brewing and winemaking procedures.
  • It’s used as a thickening agent in ice-cream, pastries, dessert, and salad dressing.
  • It’s used as a wire-drawing lubricant.
  • It’s used in labs to provide a semisolid surface for the growth of bacteria and plants in artificial conditions.
  • It’s used in papermaking and textile industries to change the absorption and wear characteristics of those materials.
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Role of Agar in Tissue Culture 

Research grade agar is advisable to be used in the lab for the culturing processes. It forms a semi-solid surface that supports the growth of explants or microbial cultures. In the suitable growth media (according to the plant to be cultured), after pH adjustment, agar is added and autoclaved for culturing purposes.

How’s Agar Prepared for Tissue Culture

Materials Required: Distilled water, MS Media, Agar, 30 grams Sugar


  1. Take a beaker and add 800 ml water to it.
  2. Add 4g of MS media, 30 grams of sugar, 10 grams of agar, and 2 ml of PPM (Plant Preservative Mixture-to avoid any kind of contamination from your cultures).
  3. Then, fill up the pitcher with 200 ml of water (to make up the volume to 1000ml or 1L).
  4. Pour 50 ml into each 8 oz container and place the lids.
  5. Place all containers in a pressure cooker and sterilize them for 20 minutes at 15 psi.
  6. After sterilization, remove the containers and keep them for cooling.
  7. Then, culture your explants in the containers containing media and agar. After carefully culturing your plants, providing proper hormones and culture conditions, and proper acclimatization of plants, you will have beautiful plants.

To shop for the tissue culture chemicals mentioned in the procedure, you can visit the Plant Cell Technology Store. Here, you will get everything you want related to your tissue culture processes.

At Plant Cell Technology, we are committed to helping our customers with their culturing processes as much as we can. The purpose of the video above is to educate our customers on the preparation of agar for plant tissue culture for beginners in the area.

PCT (Plant Cell Technology) has its tissue culture lab setups where it tests the efficiency of its products and designs protocols for culturing different plants in a laboratory environment.

Along with providing tissue culture services and equipment, PCT is also taking steps toward creating informative videos to help and educate its customers. So, don’t forget to check out our Plant Cell Technology website for more “how-to” videos.

Also, make sure to check out our other videos on our Youtube channel “PlantCellTechnology”, and don’t forget to subscribe to the channel so you don't miss any future videos from PCT. Do share your thoughts on the video and content with And, if there is any specific tissue culture topic/subject you want us to make a video about, let us know at the given email. We will do our best to bring you what you want!

Happy Culturing!


  2. ALFRED J. CROWLE, Immunodiffusion (Second Edition), Academic Press, 1973, Pages 65-206, ISBN: 9780121981563,

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