A colleague of mine has a kid in junior high school (she is 13 for context). She has a project where she needs to make a simulation of cell structure and components. Similar to the example image below:
Image from tyrocity.com
What she wants to do is make something where she can suspend objects inside a transparent medium. That medium should be able to be handled and not fall apart easily (or at all). The material should support a mold so that the shape of the end result can be controlled (like a muffin tray or cake pan). Since this is for a kids project cost will be a factor as well.
Jello or gelatin seems like a simple choice except for the fact that it would be too fragile to handle. I had initially thought about resins but the cost would be a factor for a simple project like this.
Given the loose criteria above what could we use to make a "cell" and suspend some object inside it. (She was going to use candy to represent the various parts!)