Dr Piyush Tailor

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 EQUIPMENTAND 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)

• 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.
• 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 PROCEDUR 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