Care of microscope

Care and Use of the Bright Care and Use of the Bright Field MicroscopeField Microscope

Malaria parasite

Mycobacterium tuberculosis

Importance of the MicroscopeImportance of the Microscope• Important for hematology, microbiology, TB, and

malaria testing• Compound microscope used in bacteriology, biology,

and medicine to examine minute objects such as bacteria, other unicellular organisms, and plant and animal cells and tissue

• Advances in fluorochrome stains and monoclonal antibody techniques caused growth in use of fluorescence microscopy in both biomedical analysis and cell biology

Basic Components of the MicroscopeBasic Components of the Microscopeand their functions...and their functions...

Power switchPower switch

Light intensity controlLight intensity control

CondenserCondenser

StageStage

ObjectivesObjectives

Eyepiece lensEyepiece lens

Stage motion Stage motion control knobscontrol knobs

Course and fine Course and fine adjustments adjustments knobsknobs

Field diaphragm ringField diaphragm ring

Aperture diaphragmAperture diaphragm

Care and Maintenance of the MicroscopeCare and Maintenance of the Microscope

• Good preventive maintenance and care includes: Good preventive maintenance and care includes: • Regular cleaning of oculars and objectivesRegular cleaning of oculars and objectives• Avoid damaging oculars and other optics with eye Avoid damaging oculars and other optics with eye

make-up or other debrismake-up or other debris• Careful handling to avoid abrupt motionsCareful handling to avoid abrupt motions• Protect from direct sunlight, high temperature, Protect from direct sunlight, high temperature,

humidity, dust and vibrationhumidity, dust and vibration• Use appropriate materials to clean the lensesUse appropriate materials to clean the lenses• Cover when not in use with vinyl or plastic dust cover Cover when not in use with vinyl or plastic dust cover

Cleaning the MicroscopeCleaning the MicroscopeRoutine Cleaning Supplies:Routine Cleaning Supplies:• Commercial lens tissue for optics Commercial lens tissue for optics • Caution: Do Caution: Do notnot use paper towels or use paper towels or

other rough paper productsother rough paper products• Cotton swabs with wooden shaft (optics)Cotton swabs with wooden shaft (optics)• 70% isopropyl alcohol 70% isopropyl alcohol • Dilute methanol is satisfactoryDilute methanol is satisfactory• Mild detergent and soft cloth for stage Mild detergent and soft cloth for stage

and base of microscopeand base of microscope

Cleaning Oculars and ObjectivesCleaning Oculars and Objectives• Unplug the microscopeUnplug the microscope• Wash handsWash hands• Remove dust from optical glass surfaces Remove dust from optical glass surfaces • Carefully remove eyepieces, objectives, Carefully remove eyepieces, objectives,

condenser, and filters–one at a timecondenser, and filters–one at a time• Excessive rubbing can cause damage to Excessive rubbing can cause damage to

iridescent coating on lensiridescent coating on lens• Clean and replace as completed Clean and replace as completed • Do NotDo Not take eyepiece or objectives apart take eyepiece or objectives apart

• Unplug microscope and allow bulb to Unplug microscope and allow bulb to coolcool

• Carefully place microscope on its sideCarefully place microscope on its side• Open bulb house; use tissue to remove Open bulb house; use tissue to remove

bulbbulb• Use tissue (to avoid fingerprints) to pick Use tissue (to avoid fingerprints) to pick

up new bulb up new bulb • Insert new bulb and close bulb houseInsert new bulb and close bulb house

Replacing Microscope BulbReplacing Microscope Bulb

• Plug in microscope and turn on illuminator. Rotate Plug in microscope and turn on illuminator. Rotate nosepiece to lock 10X objective in placenosepiece to lock 10X objective in place

• Place smear on stage and center it under the 10X Place smear on stage and center it under the 10X objectiveobjective

• Open the field diaphragm all the way and close Open the field diaphragm all the way and close condenser diaphragm all the waycondenser diaphragm all the way

• Move up (rack up) stage to its highest positionMove up (rack up) stage to its highest position• Adjust the oculars for interpupillary distance so that Adjust the oculars for interpupillary distance so that

only one circle of light is seenonly one circle of light is seen• Rack up condenser as high as possibleRack up condenser as high as possible

Setting the Koehler IlluminationSetting the Koehler Illumination

• Close field diaphragm half way and focus smear at 10XClose field diaphragm half way and focus smear at 10X• Close field diaphragm until diameter of illuminated Close field diaphragm until diameter of illuminated

image is smaller than the field of view image is smaller than the field of view • Lower condenser with positioning knob until you have Lower condenser with positioning knob until you have

a sharp, focused image of the edges of the field a sharp, focused image of the edges of the field diaphragmdiaphragm

• Adjust condenser using centering screws so that the Adjust condenser using centering screws so that the circle of light is centered in fieldcircle of light is centered in field

• Open field diaphragm until illuminated image is just Open field diaphragm until illuminated image is just larger than the field of view. If more light is needed, larger than the field of view. If more light is needed, use the transformer.use the transformer.

• Koehler illumination is now set. It is important not to Koehler illumination is now set. It is important not to move the condenser up or down or change the field move the condenser up or down or change the field diaphragm.diaphragm.

Setting the Koehler Illumination Setting the Koehler Illumination (continued)(continued)

Operation of the Microscope – Operation of the Microscope – Examining SmearsExamining Smears

• Put smear on stage and center it under the 10X Put smear on stage and center it under the 10X objectiveobjective

• Adjust intensity of the light to a comfortable level Adjust intensity of the light to a comfortable level with the transformerwith the transformer

• Open condenser diaphragm about 70% to achieve a Open condenser diaphragm about 70% to achieve a good balance of resolution and contrastgood balance of resolution and contrast

• Adjust oculars for interpupillary distance so that Adjust oculars for interpupillary distance so that when looking with both eyes only one circle of light when looking with both eyes only one circle of light is seenis seen

Examining SmearsExamining Smears (continued) (continued)

• Adjust sharpness of image by moving adjustment Adjust sharpness of image by moving adjustment ring on adjustable ocularring on adjustable ocular

• Once 10X focus is achieved, rotate nosepiece so that Once 10X focus is achieved, rotate nosepiece so that the 40X objective is in placethe 40X objective is in place

• Readjust the intensity of light to a comfortable level Readjust the intensity of light to a comfortable level using the transformerusing the transformer

• Use the fine adjustment knob to focus up and down Use the fine adjustment knob to focus up and down through the different planes of the fieldthrough the different planes of the field

Microscope Problems – Troubleshooting 1 Microscope Problems – Troubleshooting 1 ProblemProblem: Black Field: Black Field

Possible Causes:Possible Causes:• Microscope not plugged inMicroscope not plugged in• Power not available at outletPower not available at outlet• Illuminator not turned onIlluminator not turned on• Bulb burned outBulb burned out• Objective not clicked into placeObjective not clicked into place• Condenser too low with Condenser too low with

diaphragms closeddiaphragms closed

Microscope Problems – Troubleshooting 2 Microscope Problems – Troubleshooting 2

ProblemProblem: Field only partially illuminated: Field only partially illuminated

Possible Causes:Possible Causes:• Objective not clicked into positionObjective not clicked into position• Condenser not centered correctlyCondenser not centered correctly• Condenser too lowCondenser too low• Field diaphragms closed too muchField diaphragms closed too much

ProblemProblem: Difficulty focusing with 10X: Difficulty focusing with 10X objectiveobjective

Possible Causes:Possible Causes:• Wrong objective in placeWrong objective in place• Objective not screwed into placeObjective not screwed into place• Not in correct plane of focusNot in correct plane of focus



ProblemProblem: Difficulty focusing with 40X: Difficulty focusing with 40X objectiveobjective

Possible Causes:Possible Causes:• Not in correct plane of focus Not in correct plane of focus • Not initially focused at 10XNot initially focused at 10X


ProblemProblem: Blurry image at 10X or 40X: Blurry image at 10X or 40XPossible Causes:Possible Causes:• Dirty objectiveDirty objective• Dirty slideDirty slide• Dirty coverslipDirty coverslip

ProblemProblem: Ground glass appearance: Ground glass appearancePossible Causes:Possible Causes: • Condenser too highCondenser too high

CreditsCredits

Thanks to STD/HIV Prevention Training Center of New England

in Collaboration withState Laboratory Institute

andNational Laboratory Training Network, CDC

Care of microscope

Technology

Transcript of Care of microscope