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Test ID: CMAPD    
Chromosomal Microarray, Prenatal, Amniotic Fluid/Chorionic Villus Sampling

Specimen Type Describes the specimen type needed for testing

Varies

Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.

Provide a reason for referral with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.

 

Portions of the specimen may be used for other tests such as measuring markers for neural tube defects (eg, AFPA / Alpha-Fetoprotein, Amniotic Fluid), molecular genetic testing, biochemical testing, and chromosome and FISH testing (including AF / Chromosome Analysis, Amniotic Fluid; CVS / Chromosome Analysis, Chorionic Villus Sampling; and PAD / Prenatal Aneuploidy Detection, FISH). If additional molecular genetic or biochemical genetic testing is needed, order AFC / Amniotic Fluid Culture for Genetic Testing or FBC / Fibroblast Culture for Genetic Testing so that cultures may be set up specifically for use in these tests

 

Forms:

1. Chromosomal Microarray Prenatal Patient Information Sheet (Supply T716) in Special Instructions

2. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (Supply T576) is available in Special Instructions.

3. If not ordering electronically, submit a Cytogenetics/AFP Congenital Disorders Request Form (Supply T238) with the specimen.

 

Advise Express Mail or equivalent if not on courier service.

 

Submit only 1 of the following specimens:

 

Specimen Type: Chorionic villi

Container/Tube: 15-mL tube containing 15-mL of transport media

Specimen Volume: 20-30 mg

Collection Instructions:

1. Collect specimen by the transabdominal or transcervical method.

2. Transfer chorionic villi to a Petri dish containing transport medium.

3. Using a stereomicroscope and sterile forceps, assess the quality and quantity of the villi and remove any blood clots and maternal decidua.

 

Specimen Type: Amniotic fluid

Container/Tube: Amniotic fluid container

Specimen Volume: 20-30 mL

Collection Instructions:

1. Optimal timing for specimen collection is during 15 to 18 weeks of gestation, but specimens collected at other weeks of gestation are also accepted. Provide gestational age at the time of amniocentesis.

2. Discard the first 2 mL of amniotic fluid.

Additional Information:

1. Place the tubes in a Styrofoam container (Supply T329).

2. Fill remaining space with packing material.

3. Unavoidably, about 1% to 2% of mailed-in specimens are not viable.

4. Bloody specimens are undesirable.

5. Results will be reported and also telephoned or faxed, if requested.

 

Specimen Type: Products of conception or stillbirth

Container/Tube: Sterile container with sterile Hank's balanced salt solution (Supply T132), Ringer's solution, or normal saline

Specimen Volume: 1 cm(3) of placenta (including 50-mg chorionic villi) and 1-cm(3) biopsy specimen of muscle/fascia from the thigh

Collection Instructions: If a fetus cannot be specifically identified, collect 50-mg villus material or tissue that appears to be of fetal origin.

Additional Information:

1. Do not send entire fetus.

2. While fresher specimens prepared as described above are preferred, we can attempt analysis on specimens that have been in less-than-ideal conditions.

Forms: Final Disposition of Fetal/Stillborn Remains (if fetal specimen is sent) in Special Instructions.

 

Acceptable:

Specimen Type: Autopsy

Container/Tube: Sterile container with sterile Hank's balanced salt solution (Supply T132), Ringer's solution, or normal saline

Specimen Volume: 4 mm diameter

Collection Instructions:

1. Wash biopsy site with an antiseptic soap.

2. Thoroughly rinse area with sterile water.

3. Do not use alcohol or iodine preparations.

4. Biopsy specimens are best taken by punch biopsy to include full thickness of dermis.

Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.

Amniotic Fluid: 5 mL/Chorionic Villi: 5 mg/Muscle-Fascia: 1 cm(3)

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

Note: No specimen should be rejected. If specimen not received at appropriate temperature or in wrong anticoagulant, include note to laboratory. If questions, contact laboratory.

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.

Specimen TypeTemperatureTime
VariesAmbient (preferred)
 Refrigerated