This research project is aimed at producing a natural stain for plant and animal tissues that is inexpensive and whose sources are indigenous and abundant.
Biological stains make possible the viewing of microscopic plant and animal tissues under microscopes. When stained, the specimens are viewed clearer and they become more defined. Berries of Basella rubra (alugbati) were crushed using mortar and pestle. The crude extract obtained was filtered and used as a substitute for crystal violet as primary stain and for safranin as counterstain in the Gram staining of Bacillus subtilis and Escherichia coli. The extract was also used for staining the apical meristem of Hydrilla verticillata and the leaf of Hibiscus rosasinensis (gumamela) using the squashes technique.
The study of the microscopic details of the structures of plants usually requires some preparation of the material to facilitate observations. Some specimens show certain cellular parts nicely in a drop of water. A drop of dye, like iodine solution, however, reveals and emphasizes certain details, such as the presence of starch, which appears blue. Some structures have enough coloration that is clearly visible as is. Highly transparent and colorless structures, on the other hand, must be made visible by the use of stains.
Most of the dyes being used now in biological techniques are synthetic chemical compounds made from substances found in coal tar. Natural dyes are rarely used nowadays. In general, however, natural dyes are superior to synthetic ones in terms of permanence in microscopic examinations. They keep with the specimen for a long time while the synthetic ones easily fade away. Permanence of coloration is important especially for preparations that require considerable handling over a period of time.
Materials & Equipment
Pelczar, M., Chan, ECS and Krieg, N. Microbiology. New York, USA: McGraw-Hill Book Company, 1986.
Galicher, A.E. Essentials of Practical Microtechnique. Philadelphia, USA: Lea and Febiger, 1971.
Sass, J.E. Botanical Microtechnique. Iowa, USA: Iowa State University Press, 1958.
Further clarification of the procedures and results should be directed to the researchers and adviser.
Layah del Mundo
Karen Joy Gorospe
Anna Kristina Serquina
Ms. Juanita Cruz
Philippine Science High School