1.PURPOSE OF EXAMINATION: To lay down the procedure for preparation of 10% buffered formalin &Bouin’s fluid for tissue fixation in Histo-pathology section at NCHLS Surat.

2.PRINCIPLE AND METHOD OF PROCEDURE USED FOR EXAMINATION: Process by which the constituents of the cells and therefore, of tissues, are fixed in a chemical and partly also in a physical state so that they will withstand subsequent treatment with various reagents with a minimum loss, significant distortion or decomposition and keep the tissue in as life like a manner as possible.

3.STAFF RESPONSIBLE: lab. Technician under supervision of resident doctor/tutor.

4.PERFORMANCE CHARACTERISTICS: NA

5.TYPE OF SAMPLE: NA

6.PATIENT PREPARATION:NA

7.TYPE OF CONTAINER AND ADDITIVES: Clean, labeled plastic close container

8.REQUIRED EQUIPMENT AND REAGENTS:

Formalin: 40% formaldehyde, tap water, K2Hpo4, NaH2po4, Bouin’s fluid: Picric acid, Formaldehyde, acetic acid.

9.ENVIRONMENTAL AND SAFETY CONTROLS:Universal safety precautions

10.CALIBRATION PROCEDURE ( METROLOGICAL TRACEBILITY):NA

11.PROCEDURE(STEPS):

A: Buffered Formalin Preparation: (20 liter buffered formalin) • Take 2 liter of 40% formaldehyde solution in one big container

• Add 18 liter of tap water in container containing 40% formaldehyde.

• Mix well and add 130 gm K2HPO4 and 80 gm NaH2PO4

• Mix well till all ingredients have dissolved.

• Store this solution in closed container for use.

B: Bouin’s Fluid: 100 ml • Take 75 ml picric acid in one beaker.

• Add 25 ml of 40% Formaldehyde.

• Add 5 ml Acetic acid in it.

• Mix well and store in closed container.

12.QUALITY CONTROL PROCEDURE:NA

13.INTERFERENCE: Inadequate quality/improper dilution

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 OR CLINICAL DECISION VALUES:NA

16.REPORTABLE INTERVAL OF EXAMINATION RESULTS: NA

17.INSTRUCTION FOR DETERMINING QUANTITATIVE RESULTS WHEN RESULTS 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