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How to prepare your own sample

Task-oriented. The two prepared slides are nice — your own sample is better.

The CoreBox includes a small sample-prep kit: a blank slide, tweezers, and a pipette. That's enough for dry mounts and simple wet mounts.

Good first samples​

SampleTypeWhy it works
Onion skin (inner membrane)wet mountClassic; big clear cells, easy to peel with tweezers
Pond or vase waterwet mountMoving microlife if you're lucky
Pollen, dust, flour, salt/sugar crystalsdry mountNo liquid needed
A strand of hair, textile fibresdry mountCompare materials
Printed paper / banknotedirectHalftone dots are a great magnification test

Dry mount​

  1. Pick a tiny amount of the sample up with the tweezers and place it in the middle of the blank slide.
  2. That's it. Clip the slide into the sample holder, sample centred.

Wet mount​

  1. Put the specimen (e.g. a fingernail-sized piece of onion membrane, stretched flat) in the middle of the slide.
  2. Add one drop of water with the pipette.
  3. Lower a cover slip onto the drop edge-first, like closing a book — this pushes the air out and avoids bubbles.
✏️ TODO — Benedict

Does the kit ship cover slips? If not, either add them or document the no-cover-slip variant (works, but the water lens blurs at high magnification).

  1. Blot excess water with a paper tissue. The slide should be dry outside — the sample holder magnets and the objective both dislike water.

Mounting in the CoreBox​

  • Lift the top magnet of the sample holder, slide the slide in, sample centred over the opening.
  • Sample side towards the objective — with the 4× objective the working distance is comfortable (~18 mm), but centring matters far more than height.

Tips for a good image​

  • Thin beats interesting. One cell layer looks better than a chunk. If you can see through it against a window, it's thin enough.
  • Start with the torch de-focused / diffuse (see the troubleshooting guide) — harsh direct light hides transparent structures.
  • Onion cells are nearly transparent: try slightly oblique light (move the torch off-axis) for relief-like contrast.
🖼️ Image placeholder — diy-sample-sequence.jpg

TODO (Benedict): photo sequence of the onion-skin prep: peeling with tweezers → water drop with pipette → mounted slide in the holder → resulting phone image.