Seeing Molecules: Principles of Detection

Let’s first consider what is involved in detecting molecules. Most molecules are too small to see even with a microscope. A cell is a complex mixture of many types of small, invisible molecules.

How would you detect a specific molecule in this mixture?

There are two important considerations:

• Specificity—selectively detecting only the molecule of interest.
• Measurability—making the detected molecule of interest measurable.