How do scientists figure out what happens in a living cell?

Factual Questions
1

There are all kinds of chemicals in cells and they are used for various purposes. I really wonder how they know the processes that happen in a cell.

2

There are many types of assays using biochemical techniques, immunology, radioassays, spectroscopy etc. that have been used to characterize cellular processes. Multiple types of microscopy figure in as well. An overview:

https://www.biologydiscussion.com/cell-biology/techniques-cell-biology/top-16-techniques-used-in-cell-biology-with-diagram/26521

I was going to start out by citing microminiaturization techniques that all scientists to pilot super-tiny exploration vehicles through the bloodstream and into individual cells, but resisted the temptation.

3

One of the big ones is isotope tagging. You take some compound a cell takes up, and replace one of the elements with one of its uncommon isotopes. Then you see what other compounds that isotope shows up in. That gives big clues as to the chemical pathways.

4

Here’s a recent article about one method combining ‘stochastic optical fluctuation imaging’ (SOFI), with scanning probe microscopy. It allows observation of what’s happening in both the interior and exterior of cells simultaneously:

https://phys.org/news/2021-11-imaging-method-glimpse-cells.html?utm_source=DamnInteresting

Jackmannii, did you mean something like this?

5

I think he was talking about this.

6

I don’t want to think about how Big Pharma conspiracy paranoids are going to react to the news of shape-morphing nanobots injected directly into the bloodstream. :scream:

7

PCR and gene splicing/deactivation when you know where a protein or enzyme is coded for. There are also fluorescent-tagged strings of DNA or molecules to light up a gene, protein, or other cellular structures. You can also use chemicals that jam up an enzyme and allow for identifying downstream dependent chemical pathways. Column and thin-film chromatography, and electrophoresis separate out molecules, proteins, and DNA and show how much is in a cell relative to a common, consistently present molecule or protein. In all of this, you design an experiment or larger study around a framework built from what’s already known. It’s where giants stand on the shoulders of giants, ready for more giants to stand on their work.