Cell structure (Microscopy) 2.1.1

Microscopy, slides and more.

Light Microscopes

Poor resolution, Living samples can be examined, colour image.

TEM

High mag and res, electrons pass through.

2D Image produced

Darker areas absorb more wavelengths

SEM

High res and mag, Electrons bounce off surface.

Produces a 3D Image

Laser scanning confocal

High res, 3D Imaging, laser light creates images.

Fluorescent

View tiny sections of structures

Resolution

Minimum distance between two objects but can still be viewed as separate.

Magnification

How many times larger an object is compared to object.

Dry Mount slide

Thin slices of specimen observed with a cover slip only ontop. e.g plant tissue, hair

Wet mount

Water added to specimen before cover slip is added. Can view aquatic organisms

Squash Slide

Wet mounts but you push the cover slip down.

Smear slide

A drop of sample added on one end of slide and use edge of a slide to smear it then add coverslip.

How to calibrate

1- Line up micrometer and eyepiece graticule

2- Count how many divisions on eyepiece fit into 1 division on micrometer

3- One division on micrometer is 10 micrometers

Magnification equation

Magnification is equal to image divide by object

Differential staining

Chemical Stains used to stain different parts of the cell. E.g Crystal violet +ve charge and Nigrosin -ve charge