Which part of a compound light microscope should you use to adjust the stage and center the sample in the field of view?

• A. Objective lens
• B. Mechanical stage controls
• C. Iris diaphragm lever
• D. Coarse focus knob

Answer: (B)

Verified step by step guidance

1. Understand the function of each part of the compound light microscope: the objective lens magnifies the specimen, the iris diaphragm lever controls the amount of light, the coarse focus knob adjusts the focus by moving the stage or objective lens up and down, and the mechanical stage controls move the stage horizontally and vertically.
2. Recognize that centering the sample in the field of view requires moving the stage left-right and forward-backward without changing the focus or magnification.
3. Identify that the mechanical stage controls are specifically designed to adjust the position of the stage precisely, allowing you to center the sample under the objective lens.
4. Note that the coarse focus knob is used for focusing, not for centering the sample, and the iris diaphragm lever adjusts light intensity, not position.
5. Conclude that to adjust the stage and center the sample in the field of view, you should use the mechanical stage controls.