Microscopy: How to Centre and Identify Your Specimen
One of the most common frustrations for beginners in microscopy is losing the specimen in the field of view. Properly centring and identifying your sample is an essential skill that saves time and ensures accurate observation. Here’s a practical guide you can follow in your lab sessions.
Step-by-Step Guide
- Start with the lowest magnification – Gives the widest field of view, making it easier to locate your specimen.
- Locate a landmark – Use a large or distinctive feature in your sample as a reference point.
- Understand inverted movement – The image moves in the opposite direction of the stage.
- Make small, controlled adjustments – Use stage control knobs, not your fingers.
- Re-centre before increasing magnification – Always centre the specimen before switching objectives.
Beginner Tricks
- Dot method: Draw a tiny dot on the cover slip near your sample for easy relocation.
- Zig-zag scanning: Systematically scan to avoid missing areas.
- Slide orientation: Keep one corner facing you to maintain reference.
- Edge method: If lost, move towards a cover slip edge and return to the sample.
Image vs Stage Movement
The diagram below shows the inverted relationship between stage movement and image movement.
