Parts of a compound Microscope

ocular lens

eyepiece 10x magnification

rotating Nosepiece

the objective lenses are mounted in this part of the microscope

arm

supports the noise piece

objectivenes

magnify the image 4x,10,40x,and 100x

mechanical stage

holds the slide in position for viewing and has two adjustable knobs that control the precise movement of the slide

course adjustment

used for focusing with low power objective lens

fine adjustment

used for focusing on the high power and oil immersion lenses

aperture ( irs) diaphragm control

control the amount of light entering the substage condenser

substage condenser

not shown its below the stage. moves up and down, best to be up close to the stage

field diaphragm

to adjust the light from the bulb ( may not be present in all microscopes)

Light control rheostat

Controls level of light intensity

specimen

the object being looked at through a microscope

Resolution

the ability of the lesnes to reveal fine detail

parfocal

specimen will remain in focus as you change the objective lens

depths of field

the thickness of a plane to focus; a specimen is 3 dimensional with multiple planes to focus

field of view

portion of the slide visible when looking into the oclars

magnification on a compound microscope

scanning ( 4x) low power ( 10x) , high power dry( 40x) and oil immersion ( 100x)

ocular eyepieces has magnification of 10x

determining the total magnification

you multiply the ocular lens mg 10 times the objective lens.

example : objective lense 4x time 10 gets total of 40x magnification in other words add zero.

oil immersion

to use the 100x objective lense, a drop of oil is placed between the specimen and the scope in order to decrease bending of the light rays reflection.

basic bacterial morphologies

spherical( cocci) , rod- shape( bacilli) , spiral