Genetic and Genomic Diagnostic Lab

Specimen Requirements

Exceptions

For constitutional genetic testing: Blood is the preferred sample type unless the patient has had a blood transfusion within two weeks of sample collection or a history of heterologous bone marrow transplant (BMT). For patients with a history of heterologous BMT, a skin biopsy sample is the preferred sample type, but buccal cells can also be used as an alternative sample type for some molecular genetic testing. 

Volume

• Chromosome and/or FISH Analysis: 3-5 mL whole blood in Sodium Heparin (dark green top) tube.
• Microarray Analysis (Constitutional or Oncology): a total of 2 tubes needed; 3-4 mL of whole blood in Sodium Heparin (dark green top) tube AND 3-4 mL of peripheral blood in a EDTA (lavender top) tube.   
• Molecular Genetic Testing: 3-5 mL whole blood in EDTA (lavender top) tube. Minimum of 1 mL (for small babies). Alternate specimens (e.g., buccal cells or saliva) should be collected on patients with low white cell counts.   
• Other Tests: Please check Test Directory for specimen requirements. 

Stability

Blood can be refrigerated up to seven days before shipping. Specimens older than seven days may not pass QC metrics to perform testing. Do not freeze.

Rejection

Blood specimens may be rejected if frozen, hemolyzed or clotted.

• Cytogenetic testing: One NaHep (green top) tube containing 3-5mL whole sterile bone marrow
• Molecular testing: One EDTA (lavender top) tube containing 3-5mL whole sterile bone marrow

Exceptions 

Buccal cell samples can be used for Sanger sequencing-based molecular genetic tests only. Buccal cell samples are NOT accepted for cytogenetic tests (such as chromosome, FISH, microarray analyses) or next-generation sequencing test (such as NGS gene panels, exome sequencing, and genome sequencing); these tests require a blood sample or an alternate acceptable sample. If the patient previously had a heterologous bone marrow transplant (BMT), STR analysis will be performed, at an additional charge, in addition to the requested test to detect chimerism that could lead to an erroneous result representing the donor genotype. For patients with a history of heterologous BMT, a skin biopsy sample is the preferred sample type to use for constitutional genetic testing. 

Kits

Use only Cincinnati Children’s cytobrush (buccal cell) collection kits. Call us for overnight delivery of a buccal cell collection kit (free of charge).   

Volume

Two cytobrushes are required for targeted variant analysis or pharmacogenomic testing. Six cytobrushes are required for full gene sequencing done by Sanger sequencing.

Stability

Stable at ambient temperature for seven days after collection. Buccal specimens older than seven days can still be shipped; they will be tested if the yield and quality of DNA permit.

For submission of cultured cells from chorionic villi, amniotic fluid, skin biopsy:

Volume

One or two T-25 flasks of cultured cells in sterile culture media grown to NEAR confluence. If possible, retain at least one flask as a backup culture until analysis is completed. Unless otherwise directed, Cincinnati Children’s will establish a backup culture from submitted samples.  

Additional Requirements

For any molecular genetic testing done on prenatal specimen, maternal cell contamination study will be performed, with additional charge. With prenatal sample, please submit 3mL peripheral blood in an EDTA (lavender top) tube, saliva sample in an Oragene collection tube, or two cytobrushes from the mother.

How to Collect

• Download saliva collection instructions.
• Download saliva assisted collection instructions.

Exceptions

Saliva samples can be used for certain molecular genetic tests, such as Sanger sequencing-based tests, pharmacogenomic testing, maternal cell contamination analysis, certain gene sequencing panels, and deletion and duplication analysis by aCGH. Saliva samples are NOT accepted for cytogenetic tests (such as chromosome, FISH, microarray analyses), exome sequencing, genome sequencing, or gene panels done by genome sequencing; these tests require a blood sample or an alternate acceptable sample. For patients with a history of heterologous bone marrow transplant, skin biopsy sample is the preferred sample type to use for constitutional genetic testing, but buccal cells can also be used as an alternative sample type for some molecular genetic testing. 

Kits

Use only Cincinnati Children’s (Oragene) saliva collection kits. Call us for overnight delivery of a saliva collection kit (free of charge). 

Volume

Fill to the designated line on the collection vial.

Stability

Stable for up to one year at ambient temperature.

Extracted DNA Sample

• 10 micrograms is generally sufficient for most tests.
• If DNA is sent as a specimen, the DNA must have been extracted at a CLIA-certified and/or CAP-accredited laboratory.

Sorted Cells

You MUST call us in advance to obtain specimen requirement information and to schedule cell sorting. If sending sorted cells, >1x10⁶ is optimal. 

Fresh, Frozen Tissue Samples (Including Products of Conception)

• Fresh Tissue: At least 0.5cm x 0.5cm x 0.5 cm (100 mg) tissue sample placed in a sterile container containing tissue transport media, RPMI solution, or sterile saline. Ship at ambient temperature by overnight courier.
• Frozen Tissue: At least 0.5cm x 0.5cm x 0.5 cm (100 mg) tissue sample flash frozen and shipped on dry ice by overnight courier. Heart or muscle tissue is the preferred tissue type.    

Paraffin-Embedded Tissue

Only accepted for some oncology FISH analyses. Contact us for information.