Ordering Guidance

This test does not detect other chromosomal or structural anomalies and is intended to be ordered in conjunction with chromosomal microarray or chromosome analysis.

For detection of unbalanced translocations, deletions, or duplications, chromosomal microarray may be the more appropriate test; order CMACB / Chromosomal Microarray, Congenital, Blood; or CMAP / Chromosomal Microarray, Prenatal, Amniotic Fluid/Chorionic Villus Sampling.

Additional Testing Requirements

Normal fluorescence in situ hybridization (FISH) results will not exclude the majority of cytogenetically detectable abnormalities. As FISH testing is not a substitute for complete cytogenetic analysis, additional cytogenetic testing should be performed in conjunction with this test; order CMACB / Chromosomal Microarray, Congenital, Blood; or CHRCB / Chromosome Analysis, Congenital Disorders, Blood

Shipping Instructions

Advise Express Mail or equivalent if not on courier service.

Necessary Information

A reason for testing must be provided. The laboratory will not reject testing if this information is not provided however an applicable indication for testing may be entered by Mayo Clinic Laboratories. Appropriate testing and interpretation may be compromised or delayed.

Specimen Required

Submit only 1 of the following specimens:

Preferred:

Specimen Type: Whole blood

Container/Tube:

Preferred: Green top (sodium heparin)

Acceptable: Lavender top (EDTA) or yellow top (ACD)

Specimen Volume: 4 mL

Collection Instructions

1. Invert several times to mix blood.

2. Send whole blood specimen in original tube. Do not aliquot.

3. Other anticoagulants are not recommended and are harmful to the viability of the cells.

4. Cord blood is acceptable

Additional Information:

1. If the specimen does not grow in culture, you will be notified within 7 days of receipt.

2. Specimen cannot be frozen.

Acceptable:

Specimen Type: Fixed cell pellet

Container/Tube: Sterile container with a 3:1 fixative (methanol:glacial acetic acid)

Specimen Volume: Entire specimen

Specimen Type: Amniotic fluid

Container/Tube: Amniotic fluid container

Specimen Volume: 20 to 25 mL

Collection Instructions:

1. Optimal timing for specimen collection is during 14 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.

3. If ordering with CMAP / Chromosomal Microarray, Prenatal, Amniotic Fluid/Chorionic Villus Sampling, submit a minimum of 12 mL.

4. If ordering with CHRAF / Chromosome Analysis, Amniotic Fluid, submit a minimum of 12 mL.

5. If ordering with both CMAP and CHRAF, submit a minimum of 26 mL.

Additional Information:

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

2. Bloody specimens are undesirable.

3. If the specimen does not grow in culture, you will be notified within 7 days of receipt.

4. Specimen cannot be frozen.

Specimen Type: Chorionic villi

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

Specimen Volume: 20 to 25 mg

Collection Instructions:

1. Collect specimen by the transabdominal or transcervical method.

2. Transfer chorionic villi to a Petri dish containing transport medium (such as CVS Media (RPMI) and Small Dish (T095).

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

4. If ordering with CMAP / Chromosomal Microarray, Prenatal, Amniotic Fluid/Chorionic Villus Sampling, submit a minimum of 12 mg.

5. If ordering with CHRCV / Chromosome Analysis, Chorionic Villus Sampling, submit a minimum of 12 mg.

6. If ordering with both CMAP and CHRCV, then submit a minimum of 26 mg.

Additional Information:

1. Label each container with the specimen type, patient's name, and laboratory control number.

2. Specimen cannot be frozen.

Specimen Type: Products of conception or stillbirth

Supplies: Hank's Solution (T132)

Container/Tube: Sterile container with sterile Hank's balanced salt solution, Ringer's solution, sterile RPMI transport media, or normal saline

Specimen Volume: 1 cm(3) of placenta (including 20 mg of chorionic villi) and a 1 cm(3) biopsy specimen of muscle/fascia from the thigh

Collection Instructions:

1. Do not handle specimen with hands.

2. 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 the entire fetus.

2. If a fetus is sent, please provide a parental release form or complete the Final Disposition of Fetal/Stillborn Remains form and send it with the fetus. (A copy of this form can be found in Special Instructions.) Please note that completion of the form requires a parent's signature.

3. Specimen cannot be frozen.

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

5. Label each container with the specimen type, patient's name, and laboratory control number.

Specimen Type: Autopsy

Supplies: Hank's Solution (T132)

Container/Tube: Sterile container with sterile Hank's balanced salt solution, Ringer's solution, sterile RPMI transport media, or normal saline.

Specimen Volume: 1 cm(3) biopsy specimen of muscle/fascia from the thigh

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.

Additional Information:

1. Label each container with the specimen type, patient's name, and laboratory control number.

2. Specimen cannot be frozen.

Specimen Type: Skin biopsy

Supplies: Hank's Solution (T132)

Container/Tube: Sterile container with sterile Hank's balanced salt solution, Ringer's solution, sterile RPMI transport media, or normal saline.

Specimen Volume: 1 cm(3) biopsy specimen of muscle/fascia from the thigh

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. A local anesthetic may be used.

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

Additional Information:

1. Label each container with the specimen type, patient's name, and laboratory control number.

2. Specimen cannot be frozen.