National Science Day, 2020

On February 28, 2020, we welcomed around 60 school students on campus. Giving the usual demonstration routine a miss, we encouraged students to perform simple experiments.

Under the mentorship of TIFRH researchers, the students played a more active role in designing and performing the experiments, including interpretation of the results. 10 experiments, 60 school students and 30 mentors: a day of visualizing scientific concepts that one may have only read in a textbook.

In the Fly laboratory, students looked at various types of flies- with red and white eyes, different shapes of wings. They stained the salivary glands of flies to look into the chromosomes inside the cells.

More about the fly lab experiments: The students also looked at how genes express differently in various parts of a fly larva.

Sabyasachi, a graduate student in the laboratory for chemical space design and data science, designed a game- called MakeMol-to help students develop an intuition about the shape and structure of small molecules. The game MakeMol aims to help students grasp and understand the underlying concepts of valency, atomicity and stability of molecules.

Mechanics of Living Cells: This experiment aimed to explain forces at the cellular level, using Hooke’s Law.

Estimating packing fraction: A lot of objects in life are loose collections of ‘grains’: from piles of rice to dunes of sand. An important question is that of the actual space occupied by these structures which are disordered arrangements of the constituent grains. The experiment measured the empty space by filling it with water, in-order to estimate the Random Close Packing fraction of about 64%. The exercise was also a lesson in the errors due to small sampling sizes.

Experiments in the Sensory Biology Lab: Students observed neurons using fluorescence microscopy. Besotted by beautiful neurons, they proceeded to another activity- separating DNA molecules on a gel matrix.

Experiment in the Surface Science & Interface Engineering lab: In this lab, students assembled a lithium ion half cell (coin cell).

The school students synthesized a threonine-cysteine-isoleucine-serine tetrapeptide- ‘TCIS’. The synthesis was done by following solid phase peptide synthesis protocols. After the synthesis, the students cleaved the resin using acid and obtained the peptide. They dissolved the peptide in the solvent and analysed it through mass spectroscopy. From the correct obtained mass, they confirmed the structure of the desired peptide.

More experiments with protein chemistry: The students were given four unknown protein samples. They determined the molecular weight of the given samples by SDS-PAGE.

The Surface Dynamics Lab demonstrated the Raman Effect on the day it was first observed, 92 years ago. This novel phenomena of inelastic scattering of light (photons) by matter was discovered by C.V. Raman with assistance from his student K.S. Krishnan. A green stimulated light beam (generated by a high power pulsed IR laser source with the aid of second harmonic generation) was passed through a pressurised Hydrogen gas cell. This excites the vibrational levels of Hydrogen, giving rise to red, blue & ultraviolet light.

More experiments in the Surface Dynamics Lab: In another experiment, students measured the wavelength of helium-neon laser beam with the help diffraction grating.

Single Cell in Action and their Biology: The mini-scientists inoculated a logarithmically growing yeast culture on an agar pad and live imaged the cells under a phase contrast microscope for 100 mins. They captured cell division events. (20X, Scale bar: 10um)

The students also stained the nucleus and cytoskeleton in HeLa cells, and visualised these organelles under the microscope. (60X, Scale bar: 10um)

As the experiments drew to a close, the fly lab came up with an interesting game to explain a genetic cross. The students had to determine the genotype of fly progeny after they were given information about the parent genotypes. What a fun way to learn classical genetics!

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