## What magnification should be used for onion cells?

Place the slide under 40x magnifying lens and observe the onion cells. *note: Be careful, when focusing the microscope, not to break the glass slide with the microscope lens.

Table of Contents

**What is the size of an onion cell in micrometers?**

200 μm

2 An onion cell is about 0.2 mm in length = 0.2 × 1000 μm = 200 μm (microns). 3 Plant cells are multicellular.

**How do you make an onion cell slide on a microscope?**

Making slides

- Peel a thin, transparent layer of epidermal cells from the inside of an onion.
- Place cells on a microscope slide.
- Add a drop of water or iodine (a chemical stain).
- Lower a coverslip onto the onion cells using forceps or a mounted needle. This needs to be done gently to prevent trapping air bubbles.

### What does an onion cell observe?

Large, rectangular interlocking cells, Clearly visible distinct cell walls surrounding the cells, Dark stained nucleus, Large vacuoles at the center, Small granules may be observed inside the cells (within the cytoplasm)

**What is the field of view at 400x in micrometers μm?**

Stage micrometer at 1000x magnification with Olympus Compound Microscope. The diameter of field of view (fov) is 0.184 millimeters (184 micrometers)….

Objective | Diameter Of Field Of View | Magnification (10x Ocular) |
---|---|---|

4x | 4.0 mm (4.45) | 40x |

10x | 2.0 mm (1.78) | 100x |

40x | 0.4 mm (0.45) | 400x |

100x | 0.2 mm (0.178) | 1000x |

**How do you calculate the size of a cell under a microscope?**

Divide the number of cells in view with the diameter of the field of view to figure the estimated length of the cell. If the number of cells is 50 and the diameter you are observing is 5 millimeters in length, then one cell is 0.1 millimeter long. Measured in microns, the cell would be 1,000 microns in length.

## How do you calculate the size of a cell?

*To figure the length of one cell, divide the number of cells that cross the diameter of the field of view into the diameter of the field of view. For example, if the diameter of the field is 5 mm and you estimate that 50 cells laid end to end would cross the diameter, then 5 mm/50 cells = 0.1mm/cell.

**What can you see at 400x magnification?**

At 400x magnification you will be able to see 0.45mm, or 450 microns.

**What is the field of view at 400x?**

The diameter of field of view (fov) is 0.184 millimeters (184 micrometers). This corresponds to a 0.46 millimeter fov at 400 x magnification….

Objective | Diameter Of Field Of View | Magnification (10x Ocular) |
---|---|---|

4x | 4.0 mm (4.45) | 40x |

10x | 2.0 mm (1.78) | 100x |

40x | 0.4 mm (0.45) | 400x |

100x | 0.2 mm (0.178) | 1000x |

### What is the field diameter of 400x?

0.4 mm

Stage micrometer at 1000x magnification with Olympus Compound Microscope. The diameter of field of view (fov) is 0.184 millimeters (184 micrometers)….

Objective | Diameter Of Field Of View | Magnification (10x Ocular) |
---|---|---|

4x | 4.0 mm (4.45) | 40x |

10x | 2.0 mm (1.78) | 100x |

40x | 0.4 mm (0.45) | 400x |

100x | 0.2 mm (0.178) | 1000x |