1. PURPOSE OF EXAMINATION: To lay down the procedure for cutting the processed specimen by microtome in Histo pathology section at NSHLS Surat.

2. PRINCIPLE AND METHOD OF PROCEDURE USED FOR EXAMINATION: The method by which tissue can be sectioned & attached to a surface so that examination by microscopy can take place.

3. STAFF RESPONSIBLE: Senior Technician

4. PERFORMANCE CHARACTERISTICS:

a. LINEARITY: 3-10 micron.

b. PRECISION AND ACCURACY: NA

c. SENSITIVITY/SPECIFICITY:NA

5. TYPE OF SAMPLE: Paraffin block, Tissue cassette

6. PATIENT PREPARATION: NA

7. TYPE OF CONTAINER AND ADDITIVES: NA

8. REQUIRED EQUIPMENT AND REAGENTS:

Equipment: Microtome

Reagents: NA

9. ENVIRONMENTAL AND SAFETY CONTROL: Universal safety precautions

10. CALIBRATION PROCEDURE (METROLOGICAL TRACEBILITY): Calibration done once in a year.

11. PROCEDURE (STEPS) : • Bring the blocks on ice plate during cutting. Do rough cutting.

• Trim the blocks after putting the blocks on the ice for 15 minutes.

• First smaller tissues are cut after those bigger tissues are cut.

• Set temperature at 65 degree C in water bath.

• Insert the appropriate sharp knife (disposable) into the microtome at 45 degree angle.

• Before making ribbon of section, tight all the screws of microtome.

• To make the section ribbon set the thickness of about 3-5 micrometer.

• The ribbon is directly transferred to water bath heated up to 5-6 degree below the melting point of wax.

• Remove the creases from the ribbon and take the ribbon containing single large section or two to three sections on aluminized slide leaving preferably ¾ inch at one end for label and ½ inch on another end.

• If during removing creases any damage to the section occur then ribbon should be discarded.

• Give the same number on the slide by diamond pencil as on the block.

• Put the slides rack in to the oven at 65 degree temperature for 10 minute.

• Give xylene bath for clearing for 30 minutes.

• Rehydrate the sections by putting the slides in to increasing alcohol concentration and lastly in water.

• Now stain the sections according to standard guidelines of different types of staining procedures.

Note: Procedure for preparation of aluminized slide:

• Take white part of egg ( 4 egg approximately 50 ml)

• Take equal quantity of glycerin & 2 drops of formalin

• Mix it well & store in refrigerator.

• Apply it on slide daily as per use.

12. QUALITY CONTROL PROCEDURE: NA

13. INTERFERENCE: Poor quality paraffin

14. PRINCIPLE OF PROCEDURE FOR CALCULATING RESULTS INCLUDING, WHERE RELEVENT, THE MEASUREMENT OF UNCERTAINITY OF MEASURED QUANTITY VALUES: NA

15. BIOLOGICAL REFERENCE INTERVALS OR CLINICAL DECISION VALUES: NA

16. REPORTABLE INTERVAL OF EXAMINATION RESULTS: NA

17. INSTRUCTION FOR DETERMINING QUANTITATIVE RESULTS WHEN RESULT IS NOT WITHIN THE MEASUREMENT INTERVAL: NA

18. ALERT /CRITICAL VALUES WHERE APPROPRIATE: NA

19. LABORATORY CLINICAL INTERPRETATION: NA

20. POTENTIAL SOURCE OF VARIATION: NA

21. REFERENCE: Histopathological laboratory techniques by Bancroft, 6th edition