Question

What are the principles of tests used to study signal transduction?

Answer 1

Changes in the transcription or translation of genes, and post-translational and conformational changes in proteins, as well as changes in their location.

Explanation:

Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events,
The changes elicited by ligand binding (or signal sensing) in a receptor give rise to a signaling cascade. At the molecular level, such responses include changes in the transcription or translation of genes, and post-translational and conformational changes in proteins, as well as changes in their location.

As with other signals, the transduction of biological signals is characterised by delay, noise, signal feedback and feedforward and interference, which can range from negligible to pathological.
https://en.wikipedia.org/wiki/Signal_transduction

http://themedicalbiochemistrypage.org/signal-transduction.php