Sop for laboratory compound microscope

This Document describes (Standard Operating procedure) Sop for cleaning and operation of laboratory compound microscope

Sop for cleaning and operation of laboratory compound microscope

I. Purpose & Scope:

  • The purpose of this SOP is to lay down the procedure for  cleaning and operation of laboratory compound microscope .
  • This Standard operating procedure shall be applicable for cleaning and operation of laboratory compound microscope . in the Microbiology section of Quality Control Department

II. Responsibilities:

  • All Quality control personnel shall be responsible to follow and implement this SOP.

III : Introduction and Procedural Part :

Precautions :

  • The optical microscope is a delicate instrument; it should be handled by experienced staff.
  • Do not disturb the optical system.
  • The cleaning of the microscope shall be done by Microbiologist.
  • The microscope should be properly cleaned before and after every use.
  • The instrument should be always kept in its cover when not in use.

Requirements for cleaning :

  • Tissue paper, Butter paper sheet, Xylene solvent or 20% IPA

Cleaning of laboratory compound microscope : 

  • Place the microscope on a plane surface.
  • Remove the cover of the microscope.
  • Unscrew the eyepieces of microscope and place on a sheet of tissue paper.
  • Unscrew the individual eyepiece and remove ocular lens.
  • Wipe the lens of each eyepiece with a piece of tissue paper moistened with a xylene or 20% IPA.
  • Hold the lens against soft light and check for any spots or patches.
  • If any spots are observed, take a dry piece of tissue paper and wipe again carefully.
  • Replace the ocular lenses by screwing them back.
  • Wipe the distal lenses of the eyepiece with another tissue paper.
  • Replace the eyepieces in the respective sockets.
  • Unscrew the objective lenses one by one and place on a sheet of tissue paper.
  • Moisten a piece of tissue paper with a little xylene and rub on the lens.
  • Take another piece of a tissue paper moistened in xylene and clean the oil-immersion objectives (45X and 100X) carefully.
  • Wipe the lenses after cleaning, with a piece of dry tissue paper.
  • Replace the lenses carefully in their respective sockets.
  • Remove the condenser assembly carefully and place on the sheet of paper.
  • Remove the lenses of the condenser and clean them with a piece of dry tissue paper.
  • Reassemble the condenser unit and fit in its place.
  • Clean the light aperture in a similar manner.
  • After cleaning is over, ensure that all the components removed for cleaning are fitted in their respective sockets in a proper manner.
  • Cover the microscope, when not in use.


Operation of laboratory compound microscope :

  • Connect the power chord to electric mains. Switch “ON” the lamp of the
  • Place the specimen slide in the slide holder on the stage of the microscope.
  • With the help of condenser knob, adjust the intensity of light falling on the slide.
  • Make preliminary observation through 10X objective and adjust the light required.
  • Adjust the view through 45X objective and using the coarse and fine-adjustment knobs, focus the objective until a sharp image is observed.
  • Place a drop of cedar-wood oil on the smear. Rotate the oil-immersion objective in place and use only the fine-adjustment knob for focusing.
  • Record observations in the appropriate format and slowly raise the objective from the slide surface.
  • Clean the oil immersion objective using a piece of soft tissue paper dipped in xylene.
  • Wipe again the oil immersion objective with a dry piece of tissue paper. Ensure that no residues of oil to remain on the lens.
  • Cover the microscope when not in use.

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