======Procedure for Cholinesterase examination======
*Learn operation of [[Erba XL-640]] and [[Erbachem]].
  *Select equipment  
    *Use Erba XL-640 as peferred equipment.
    *If Erba XL-640 is malfunctioning and can not be repaired within period acceptable to clinicians, use Erbachem and follow [[procedure for responding to Erba XL-640 failure]]
  *Read following documents

|**references**|{{CHE_Randox_kit literature.pdf|Cholinesterase Kit literature of RANDOX}}| 
| |**Note:** When a new lot is opened, verify kit literature with the uploaded version.|
| |[[lis_upload_dokuwiki_media|Upload]] newer version when required and make necessary changes in procedure and process|

|**environmental and safety controls**|{{CHE_Randox.pdf|MSDS of CHE Randox Kits}}|




|The examination is done on Erbachem and Erba XL-640|

|[[Follow this SOP for RANDOX Reagent]]|
|Procedure for [[Preparing CHE reagent]]|
|[[test parameter for CHE in Erba XL-640]]|
|[[Centrifugation]]|
|[[Preparing aliquot]]|
======ERBA XL-640=====

  -Currently, testing of CHE is done in ERBA XL-640.
  -The reagent is kept in the freezer of refrigerator no.11.
        * NOTE-Preparation Of Reagent Rack
        * Prepare 1 ml reagent aliquot in washed plain vacutee and arrange in thermocol rack with qc 5 cups which is shown below. Every time when sample come, pick one reagent aliquote with one qc 5 cup and run it. Give proper code for QC (520062209)so it will be exported in LJ. if more than one sample run at one time,take only one qc 5 cup and take 2 reagent vacuttee and mix it in one(total volume will be 2 ml) because from 1 ml reagent only 2 tests can be done.{{ :nchsls:c:biochemistry:document:che_rack_with_qc_cup.jpg |}}
  -It has to be melted only when sample has to be tested for CHE.
  -Value of QC 5 (normal range) or QC 8 (abnormal range) are very similar so only one level quality control(QC 5 Normal Range) has to be used as quality control.
  -Sample as well as QC ( QC 5 ) is diluted 5 times, CHE is selected, testing is done.
  -Entry of sample is done as it is, no suffix i.e. dil is added.
  -QC 5 done every time whenever test done.
  -if more than one sample run at one time,only one qc 5 is need to be done.
  -Every time before analysis the sample is diluted. For that precaution should be taken. the water to be taken should be clean DI water labelled  from the "frige 12" which is QC WATER.


======Erbachem====== 

**Note:** Following instruction is useful only if operator is familiar with [[Erbachem]]
^Parameter^Value^
^Sample volume(ul)|10|
^Reagent volume(ul)|775|
^Filter|405 nm|
^Aspitation Volume(ul)|500|
^Type of reaction|2 point|
^Decimal place|1|
^Delay time |30sec|
^Reading time |60sec|


^Calibration, Result calculation, Quality control and sample examination in Erbachem^
^Prepare for calibration as below when lot changes or there is relevent NC. Refer [[Calibrator and QC]]^
^testing material^Replicates^
|Water blank|2|
|Normal Range Calibrator|4|
|Abnormal range Calibrator|4|
|Normal Range Control|4|
|Abnormal range Control|4|

  -Run all testing material as sample (as described below at **Sample Examination**)
  -Evaluate calibration and QC absorbances in spreadsheet. Compare with past results.
  -If results are acceptable, enter the factor in the erbachem and set decimal place to zero.
====sample examination==== 
  -Check aspiration volume of 500 microliter in test parameter of CHE.
  -Run Randox Human assy control-2(QC 5),1 Randox Human assy control-3(QC 8) in each and every batch. See Assigned values of target values of QC [[Calibrator and QC Targets|here]]
  -Take 775 microliter reagent of ependroff cup from deep freeze no.6. See procedure for [[Preparing CHE epindroff cups]].		
  -Add 10 microliter sample to it  			
  -Take reading immediately at 405 nm.
  -Select "Run test" -> CHE in Erbachem menu.
  -When instrument asks "Aspirate water", aspirate water.
  -Take reading immediately at 405 nm.	
  -Total time taken for analysis is 90 seconds. (delay time 30 seconds + reading time 60 seconds)
  -Evaluate QC results. If QC results show major deviation from past, rerun batch.
  -[[lis_calibration_entry|Enter Calibration in LIS]]
  -[[list_qc_entry_manual|Enter QC results manually in LIS]]
  -[[list_result_entry_manual|Enter sample results manually in LIS]]
  -**instructions for determining quantitative results when a result is not within the measurement interval:** Dilution of sample with DI water is done in same way as done by Erba XL-640 automatically.