Fixing a sample with formaldehyde and pickling a sample in ethyl alcohol?

Fixing a sample with formaldehyde involves using a solution of formaldehyde to cross-link proteins and preserve the tissue structure, making it ideal for histological studies. This process stabilizes cellular components, preventing degradation and allowing for detailed examination under a microscope. In contrast, pickling a sample in ethyl alcohol involves immersing it in alcohol to dehydrate and preserve it, which can also enhance clarity for certain types of analysis. Both methods serve to maintain the integrity of biological specimens for further investigation.