Learn by Doing: Visualizing Embryos and Building Microscopes with High Schools

Dr. Sherrard organized an MBL ROCs project where students built their own light microscope and used it to take pictures of embryos. The project was held virtually over zoom at Yale University with 25 students from several high schools across Connecticut. The class involved a lesson about microscopy and embryology, followed by sessions in small groups where each student built their own microscope alongside one of five MBL alumni scientists. Students used their microscopes to visualize an array of butterfly wings, as well as frog, chick, fly, and annelid embryos, and were also shown live wild type and mutant zebrafish embryos at different stages of development. The overall goal of the class was to share our passion for science and inspire interest in developmental biology and science generally.

Overall goals

The overall goals of the project were to:

1. Learn concepts of light microscopy and embryology
2. Build a light microscope
3. Visualize and identify embryo stages and structures

Background

Microscopy is a major tool in biology and is critical in understanding and manipulating cell fate and function. Using microscopy to visualize cells across organismal and molecular scales, we have gained an understanding of many of the principles that define cell behavior; including processes that regulate cell division, migration, and differentiation during development. Many questions however remain unanswered, and the primary goal of this class was to give students the opportunity to do real microscopy experiments and gain an understanding of what it is like to be a scientist, with the ultimate objective to inspire students to pursue a career in science. This project was inspired by the embryology course at the MBL and we hoped to excite and motivate our class just like the MBL did for us. Our team works in the Giraldez lab at Yale University, where the event was held, and will again occur as an in-person event this summer.

Activities

Goal 1: Learn concepts of light microscopy and embryology

We started our project with an interactive presentation where five scientists from the Giraldez lab, all of which are MBL alumni, explained concepts of microscopy and embryology. This included an explanation of basic optics and magnification, as well as fluorescence microscopy and early embryo development. We used data from our research and showed live zebrafish embryos in a time course of development (images below), from a single cell to a fully developed fish, and demonstrated genetic manipulation using a mutant line that lacked a gene important for pigmentation. This was a great chance for us to get to know the students and answer questions about our work and what it is like to be a scientist.

Goal 2: Build a light microscope

To build the microscopes, we used instructions from Bob Goldstein’s lab and pre-prepared several parts and made a manual to assist the students. Each teacher worked with 5 students and demonstrated how to build the microscopes as they built their own alongside. The setup used a piece of wood that students put screws through and attached adjustable layers of plexiglass. By placing a light in direct line with the objective, sample, and camera (students used a smart phone), and moving the plexiglass to focus, students were able to take pictures of samples which they put in the light path (see below). We trouble shot with students and ensured our groups could all successfully focus a sample using their microscope. Download instructions for building your own microscope here.

Goal 3: Visualize and identify embryo stages and structures

In the final part of the class, students used their microscope to visualize a set of slides we gave them. Students were given three slides of chick and frog embryos at different stages of development, which we looked at together in a group and discussed the order of the stages as well as the developmental processes occurring during this time course. Students also visualized slides with annelids, butterfly wings, and drosophila embryos (examples below). At the end of the class, we brought the groups back together and had a discussion about the slides and what students learnt from the class, and also encouraged and suggested ideas of other objects they could image after the class.  

Impact

Each student was able to successfully and independently build their microscope and acquire images using slides we gave them, and also had the chance to be creative by imaging items of their choosing. Overall, we hope our class gave them ownership of their work and confidence in their abilities to have a future in science. The DIY microscopes were very simple to build and used reagents that are affordable and easily accessible. The class can be adapted for student age and provides a memorable and engaging lesson platform to understand scientific ideas from crystals and cells, to development and optics.

Reflections

The project was a very enjoyable experience for all of our team and we had great feedback, where students most enjoyed building and using the microscopes, as well as seeing our live embryos develop! We are really excited to host similar events in the future and hope to promote this class in teaching generally.