====4.Tissue processing====


**1.PURPOSE OF EXAMINATION**
For processing the biopsy tissues in a manner so as to ensure optimal results. 

**2.PRINCIPLE AND METHOD OF PROCEDURE USED FOR EXAMINATION**
 As per instructions & operating manual of automated tissue processor manufacture.

**3.STAFF RESPONSIBLE**
Senior technician

**4.PERFORMANCE CHARACTERISTICS**
NA

**5.TYPE OF SAMPLE**
Tissue bits (after grossing).

**6.PATIENT PREAPARATION**
NA

**7.TYPE OF CONTAINER AND ADDITIVES**
Perforated cassettes

**8.REQUIRED EQUIPMENT AND REAGENTS**
Equipment: automatic tissue processor.
Reagent: Alcohol (ascending grades), Xylene, Paraffin. 

**9.ENVIRONMENTAL AND SAFETY CONTROLS**
Universal safety precaution

**10.CALIBRATION PROCEDURE (METROLOGICAL TRACEBILITY)**
calibration done once in a year through EQDC. 

**11.PROCEDURE (STEPS)**
__**By automated tissue processor**__
  *First lift up the lead of tissue processor (1st container) & hang the tissue basket in hook present in lead
  *Switch on the UPS
  *Timer is preset as per follow:
  -10% formalin -5 to 6 hrs
  -50% alcohol – 1hr
  -60% alcohol – 1hr
  -70% alcohol – 1hr
  -80% alcohol – 1hr
  -90% alcohol – 1hr
  -100% absolute alcohol -1hr
  - Xylene 1-1 ½ hr
  - Xylene 2-1 ½ hr
  - Paraffin wax 1 -1hr
  - Paraffin wax 2-1hr
  *After 16 hrs (next day) switch off the instrument and take the tissue basket from processor.


__**Manual Tissue Processing**__
  -Take 2 glass beaker of 500 ml capacity and add 70% acetone in first one and 80% of acetone in second beaker. put tissue cassette in first beaker  for 30 minute
  -After 30 minute remove tissue bucket from first bucket and put in second bucket for 30minute.
  -Replace acetone of first bucket with 90% acetone.
  -After 30 minute remove tissue bucket from second bucket and put in first bucket of 90% acetone for 30minute.
  -Replace acetone of first bucket with 100% acetone.
  -After 30 minute remove tissue bucket from first bucket and put in second bucket of 100% acetone for 30minute.
  -After these steps tissue cassettes are kept in xylene for two changes each for 1 hour.
  -Then cassettes are transferred to wax bath of histokinet. 
  -Wax bath is connected with electric power; wait till temperature reach at 65 C. put bucket inside for one hour.
  -After 1 ½ hour remove cassettes from it add new wax in wax bath and again keep cassettes for 1 ½ hour.
  -Tissue is ready for embedding. 


**12.QUALITY CONTROL PROCEDURE**
NA

**13.INTERFERENCE**
 NA

**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 RESULTS IS NOT WITHIN THE MEASUREMENT INTERVAL**
NA

**18.ALERT/ CRITICAL VALUE, WHERE APPROPRIATE**
NA

**19.LABORATORY CLINICAL INTERPRETATION**
NA

**20.POTENTIAL SOURCE OF VARIATION**
NA

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