Introduction:
Method of making plant primary color specimens 1
1, specific steps:
(1) Poisoning: Rinse the collected plants with distilled water, soak them in 70% alcohol for 5min, then soak them in distilled water 15min, and rinse them for 2-3 times until the representative surface is clean.
(2) Soak in copper sulfate containing 5% biocide for three days and rinse.
(3) Preservation solution: 30 ml of 6% sulfurous acid; 30ml glycerol; 30 ml of 95% alcohol (by volume); 900ml water.
2. Principles:
In order to increase the color retention and anti-corrosion effect, appropriate amount of boric acid, glycerol and carbolic acid should be added.
Sulfurous acid is a strong acid, which is easily oxidized into sulfuric acid, so it has a strong antiseptic effect and is a good preservation solution with good transparency. However, its disadvantage is that sulfurous acid is unstable and easy to decompose, releasing sulfur dioxide, which has bleaching effect, so it is necessary to master the concentration when using it.
Formalin can change the structure of protein and make it solidify. It is an efficient disinfectant and a common biological preservative. Easy to purchase and popularize.
3. Advantages and disadvantages:
Advantages: Good green keeping effect, closer to the natural color of plants growing in real environment.
Disadvantages: 1) Sulfur dioxide produced by sulfurous acid is toxic to human body; 2) The operation time is long, which takes 4-5 days; 3) After being stored for more than half a year, biofilms are easy to form on the surface, and the preservation solution can be changed in time. However, for some new fruits (such as cucumbers), it is not easy to change the preservation solution, and the fruits will disappear if you are not careful; 4) Compared with the second method, the preservation solution is easy to turn yellow.
Method of making plant primary color specimens II
1. Specific operation steps: firstly, slowly add copper sulfate powder into 50% acetic acid, and gently stir with a glass rod until the powder no longer dissolves, which is a saturated solution (about 10-20g copper sulfate powder is added into 100ml acetic acid solution). Take this as the stock solution, dilute it 3-4 times with water, then heat it to 70-80 degrees Celsius, and put the cleaned specimen into this preservation solution. Pay attention to constantly turning the specimen, so that it is heated evenly and all of it comes into contact with the liquid medicine. At first, the original green color of the specimen will recede, but after a few minutes to half an hour, the green color will return. At this time, stop heating, gently take out the specimen, rinse it with water, and put it into the prepared preservation solution (5% formalin). The color of the specimen can be preserved for more than ten years, which is considered as the best way to preserve the green of the specimen.
2. Principle: The cells of green plants contain chloroplasts, mainly chlorophyll, which contains magnesium ions. Chlorophyll can lose magnesium ion under the action of acid and become dark brown "pheophytin", also called plant melanin. At this time, if copper ions are used instead of magnesium, chlorophyll can be restored to green, which is more stable than that of magnesium ions and can be preserved for a long time.