Microscopes are used to [?] evidence found at the scene of a crime.

Most schools use [?] Microscopes. These use lenses to magnify specimens, usually up to a [?] of 400x.



A light microscope consists of

(a) A [?], to reflect light towards the specimen.

(b) A [?], to hold and support the specimen

(b) An [?] lens, to refract and focus the light.

(c) An [?] lens, to view the image of the specimen.

(d) [?] knobs, to move the lenses so that a clear image of the object can be seen.

Light microscopes are often used by forensic scientists to analyse samples of hair.
They can be used to identify the [?] of the hair, and to determine if the air is curly or [?]. They can also be used to measure the [?] of the hair.

Light microscopes can also be used to identify fibres collected at the scene of the crime. These fibres can be either natural or [?]. Sometimes, it is more convenient to compare samples by using a [?] microscope, so that the two samples can be seen side by side.


There are other types of microscopes used by forensic scientists.

1. [?] microscopes

These microsopes are able to offer magnifications up to 1 000 000 x . They are able to offer a greater resoution than optical microscppes, so that finer details can be observed.
The focusing is achieved by using electromagnets.

2. [?] microscopes

These microsopes are invaluable in comparing a sample found at the scene of a crime to a sample taken from the suspect. They can be used for comparing a test bullet from a suspect's [?] to a bullet found at the scene of the crime. This amalysis is possible because marks, called [?], are different from gun to gun. These marks are caused as the bullet is [?] from the gun.

3. [?] microscpes

Two polarising [?] are used. A sample is placed between the filters, on the stage of the microscope. When the sample is rotated, it changes [?] when viewed though the eyepiece.
This method is particulary useful when analysing minerals, and crystals. It can also used for identifying the [?] found in paint samples.