=====SOP FOR TISSUE FIXATION=====

**1.	PURPOSE OF EXAMINATION:** To lay down the procedure for Specimen Fixation in Histo-pathology section at NCHLS Surat

**2.	PRINCIPLE AND METHOD OF PROCEDURE USED FOR EXAMINATION:** Formalin preserves the tissue in life like state. Approximately 16-24 hrs requires for adequate fixation. The penetration capacity of formalin is 1 cm so large specimens shall be cut into multiple slices of 1 cm thickness.

**3.	PERFORMANCE CHARACTERISTICS:** NA

**4.	TYPE OF SAMPLE:** Biopsy/ Excised specimen

**5.	PATIENT PREPARATION:** NA

**6.	TYPE OF CONTAINER AND ADDITIVES:** Plastic close container

**7.	REQUIRED EQUIPMENT AND REAGENT:** 10% Neutral buffer formalin / Bouin’s fluid.

**8.	ENVIRONMENTAL AND SAFETY CONTROLS:** Universal safety precautions

**9.	CALIBRATION PROCEDURE(METROLOGICAL TRACEBILITY):** NA

**10.	PROCEDURE(STEPS):**

•	For routine histopathological examination specimen should be sliced 1cm apart , put cotton soaked in 10% formalin inside it submerged in 10% buffered formalin (volume of formalin should be 10 times of the specimen) and for frozen section examination tissue should be received in normal saline.

•	If the specimen is large. Cut the specimen in smaller slice with proper orientation with 1 cm thickness.

•	If fixative is hemorrhagic, change the formalin.

•	Keep the received specimen and respective requisition form at proper suitable place.

**11.	QUALITY CONTROL PROCEDURE:** NA

**12.	INTERFERENCE:** Formalin pigment.

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

**14.	BIOLOGICAL REFERENCE INTERVALS OR CLINICAL DECISION VALUES:** NA

**15.	REPORTABLE INTERVAL OF EXAMINATION RESULTS:** NA

**16.	INSTRUCTION FOR DETERMINING QUANTITATIVE RESULTS WHEN RESULTS IS NOT WITHIN THE MEASUREMENT INTERVAL:** NA

**17.	ALERT/CRITICAL VALUE, WHERE APPROPRIATE:** Autolysed specimen

**18.	 LABORATORY CLINICAL INTERPRETATION:**NA

**19.	 POTENTIAL SOURCE OF VARIATION:** NA

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