Identity Testing - MCC Studies, Zygosity

Alternate test name

Maternal Cell Contamination Studies, Zygosity

Lab area

Genome Diagnostics - Molecular Genetics

Method and equipment

STR (short tandem repeat) analysis

Expected turn-around time

Prenatal samples: 2 weeks Pregnancy/STAT: 2-3 weeks Routine: 4-6 week

Specimen type

Blood
gDNA
cultured amniocytes
chorionic villus

For details about specimen requirements, please refer to: Specimen Type & Requirements (PDF).

Specimen requirements

Blood: 5-10 mL in EDTA, 0.5 mL in EDTA (neonate);
DNA-minimum 10 ug in 100 uL low TE (pH8.0)

If sending a prenatal sample, please contact the laboratory prior to sending sample to discuss sample requirements.

Storage and transportation

Blood, DNA: Room Temperature

For details about specimen requirements, please refer to: Specimen Type and Requirements

Special requirements

Special Instructions for Genome Diagnostics Samples

If sample shipment >48 hours, ship on ice.

Shipping information

The Hospital for Sick Children

Division of Genome Diagnostics

555 University Avenue, Black Wing, Room 3416

Toronto, ON

Canada

M5G 1X8

Phone: 416-813-7200 ext. 2

Hours: Monday to Friday, 8 a.m. to 4:30 p.m.

Off hours: Please send to Rapid Response Laboratory, 555 University Avenue, Room 3642

Email Molecular Lab: molecular.lab@sickkids.ca

Email Cytogenetics: cytogenetics.requests@sickkids.ca

Requisition

Identity Testing - MCC Studies, Zygosity - requisition

Background and clinical significance

Individuals can be distinguished from one another by DNA fingerprinting, which compares nine to sixteen variable DNA markers in different regions of the genome. Each person has their own pattern of markers - a DNA ‘fingerprint’. PCR amplification followed by gel electrophoresis allows comparison of these markers from different individuals. This method can be used to determine the biological relationships between family members such as identity and zygosity testing. Determining the relationships between family members can be very important if a genetic cause for a disease is being considered, since the genetic diagnosis of one family member may apply to the other family members as well. DNA fingerprinting can also be used to evaluate the purity of tissue samples obtained for other kinds of tests. Maternal cell contamination of fetal cell samples obtained for prenatal analysis can be assessed in this way, and sample mix-ups or labeling errors can be detected by using DNA fingerprinting to match tissue samples from the same person taken at different times. DNA fingerprinting is also used to distinguish between the X and Y chromosomes for sex determination.

See related information sheets:

Identity Testing Zygosity Testing

Identity Testing MCC/Fetal Sexing

Disease condition

Maternal Cell Contamination (MCC)

Zygosity Testing