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23213 Acetylcholinesterase, Amniotic Fluid (ACHE)

Acetylcholinesterase, Amniotic Fluid (ACHE)
Test Code: AFACESO
Synonyms/Keywords
​Ref Lab Code: 9287, AChE-AF (Acetylcholinesterase, Amniotic Fluid), Amniotic Fluid, Acetylcholinesterase
Useful For
​Diagnosing open neural tube defects, and to a lesser degree, ventral wall defect
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
Amniotic fluid ​ Amniotic fluid container​ ​ 1 mL​ 0.3 mL​ ​
Collection Processing Instructions
​1. A specimen from the 14 to 18 week gestational period of pregnancy is preferred. Amniotic fluid from the 14 to 21 week gestational period is acceptable.
2. Do not centrifuge.
Additional Information:
1. Gestational age at amniocentesis is required.
2. If chromosome studies are also requested, see AF/8426 Chromosome Analysis, Amniotic Fluid. The specimen for acetylcholinesterase testing, when requested with chromosome analysis, cannot be frozen.
Forms:
1. Second Trimester Maternal Screening Alpha-Fetoprotein (AFP)/QUAD Screen Patient Information Sheet is required; see Special Instructions
Specimen Stability Information
Specimen Type Temperature Time
Amniotic Fld​ ​ ​ Refrigerated (preferred)​ 365 days​
Frozen ​ 365 days​
Ambient ​ 14 days​
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Mayo Medical Laboratories​
 Tuesday, Thursday​ 4 days​
Polyacrylamide Electrophoresis​
Reference Lab
Mayo Clinic Laboratories
Reference Range Information
Negative (reported as negative [normal] or positive [abnormal] for inhibitable AChE). Reference values were established in conjuction with alpha-fetoprotein testing and include only amniotic fluids from pregnancies between 14 and 21 wk gestation, with 16 to 18 weeks being preferred.
Interpretation
​The presence of acetylcholinesterase in amniotic fluid is positive for a neural tube defect if fetal hemoglobin contamination can be ruled out.
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​82013 ​ ​ ​ ​
Synonyms/Keywords
​Ref Lab Code: 9287, AChE-AF (Acetylcholinesterase, Amniotic Fluid), Amniotic Fluid, Acetylcholinesterase
Ordering Applications
Ordering Application Description
​Centricity ​Amnio Acetylcholines
​Cerner ​Acetylcholinesterase Amniotic Fluid (ACHE)
​COM ​Amnio Acetylcholinestase, Mayo
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
Amniotic fluid ​ Amniotic fluid container​ ​ 1 mL​ 0.3 mL​ ​
Collection Processing
​1. A specimen from the 14 to 18 week gestational period of pregnancy is preferred. Amniotic fluid from the 14 to 21 week gestational period is acceptable.
2. Do not centrifuge.
Additional Information:
1. Gestational age at amniocentesis is required.
2. If chromosome studies are also requested, see AF/8426 Chromosome Analysis, Amniotic Fluid. The specimen for acetylcholinesterase testing, when requested with chromosome analysis, cannot be frozen.
Forms:
1. Second Trimester Maternal Screening Alpha-Fetoprotein (AFP)/QUAD Screen Patient Information Sheet is required; see Special Instructions
Specimen Stability Information
Specimen Type Temperature Time
Amniotic Fld​ ​ ​ Refrigerated (preferred)​ 365 days​
Frozen ​ 365 days​
Ambient ​ 14 days​
Useful For
​Diagnosing open neural tube defects, and to a lesser degree, ventral wall defect
Reference Range Information
Negative (reported as negative [normal] or positive [abnormal] for inhibitable AChE). Reference values were established in conjuction with alpha-fetoprotein testing and include only amniotic fluids from pregnancies between 14 and 21 wk gestation, with 16 to 18 weeks being preferred.
Interpretation
​The presence of acetylcholinesterase in amniotic fluid is positive for a neural tube defect if fetal hemoglobin contamination can be ruled out.
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Mayo Medical Laboratories​
 Tuesday, Thursday​ 4 days​
Polyacrylamide Electrophoresis​
Reference Lab
Mayo Clinic Laboratories
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​82013 ​ ​ ​ ​
For most current information refer to the Marshfield Laboratory online reference manual.