A Sticky Situation

This weekend I played with corn. Cornstarch to be exact. I picked up two $1 packages at Walmart and was playing around with mixing different concentrations. I know cornstarch as a fun camp activity I did with kids in Honduras. When you add enough cornstarch to water, it appears to be a liquid, but when it undergoes stress compacts into a rigid solid. I know that gravy recipes call for cornstarch to thicken them. So, I added about 10 teaspoons of cornstarch to 1/2 cup of water, and microwaved it. Lo and behold, it thickened into a lovely gel. Well, I can't say lovely. It was a disgusting pale white color with a layer of moist cornstarch that had not gelled on top. I played around with it some more, and found that 5 teaspoons in 1/2 cup of water made a nice gel. One problem I could see was that as I microwaved it, the gel heated and rose up considerably. When it cooled it continued to stick on the sides of the glass jar, while the center collapsed. It was pretty gross, and a very uneven surface. I'm hoping the pressure cooker heats it evenly so that I don't have this problem, and have to smooth it out after I sterilize it. Also, the white color makes it look like it is already contaminated with bacteria. It will be really hard to spot infection if it occurs, unless I dye it some ridiculous neon color. Which I will likely end up doing.

If corn sneezed, this would come out.

Speaking of the pressure cooker, I finally assembled it! It looks very nice. I have to rinse all the parts before I can safely use it, but from what I can see it seals very well.

I'm collecting some jars, and may have to buy some cheap baby food. I currently have 5 jars, and would like 10-15.

I was told that this project is confusing, and I use a lot of botanical jargon. So here I will attempt to do a basic explanation of tissue culture. It is a scientific concept though, so I can not avoid a few terms.

Tissue culture is used to clone plants. This is not done the DNA-splicing techniques that are often associated with cloning labs. Cells are able to rapidly divide and preserve their DNA and traits in a process called asexual (without sex) reproduction. When this happens, exact copies are made of the original cells. In a normal environment, plant cells, or tissue, cannot grow very fast because of disease, contaminants, being eaten, etc. Additionally, plant tissue needs a lot of food to grow and divide at a fast pace.

What tissue culture aims to do is provide the perfect environment for cell division and plant growth. It does this by placing a tissue sample in a sterile environment, typically a glass jar. This jar has a sterile gel in it that is firm enough to allow the tissue to anchor itself and grow, while also supplying all of the energy and nutrients necessary for growth. When these two factors are present, the cells can grow and divide uninhibited.

As a tissue sample (a leaf for instance) divides, it forms a clump of cells called a callus. New growth points (the center of a plant where leaves and roots come from) emerge, and generate dozens or even hundreds of new plants. These are then divided and places in their own jars, where they will again divide. Different chemicals can be added (like the root hormone I mentioned earlier) that will stimulate certain growth in the plants to further establish them. When the plants are large enough they are removed from the jars and gradually introduced to real growing environments.

Now here is a description of the materials I am using:

A plastic box as a pseudo-sterile hood: By cutting a hole in the side and spraying it down with bleach, this place becomes a safe place to work free of contamination. Bacteria and mold spores cannot "fall" into the jars because the top is covered.

91% isopropyl alcohol, 70% isopropyl alcohol, 3% Hydrogen peroxide, 8.5% bleach: All of these are used to sterilize the tissue and cultures. Different combinations are used to effectively kill everything bad.

Pressure cooker: Pressure cookers do not let steam evaporating inside to escape, creating an environment with 15 pounds per square inch of force and high temperatures. These conditions sterilize things that would be hard to clean with chemicals.

20-20-20 fertilizer: 20-20-20 is a ratio of Nitrogen-Phosphorous-Potassium, which are three major nutrients plants need for good growth. It also has a lot of other good things.

Multivitamin: Another great nutrient source that covers all the bases.

Inositol: I honestly don't know exactly what this does. Claims say that it is a natural chemical that aids in nutrient absorption by cells. It may help the tissue samples to absorb the food I'm providing and help them grow.

Agar/cornstarch: These are natural ingredients that, when heated in a mixture of water, will turn into gels. This provides a surface that the tissue samples can anchor and grow into, as well as easily passing on the nutrients to the growing cells.

I hope this helps!