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Test Catalog

Test ID: SEQF    
Sequential Maternal Screening, Part 2, Serum

Specimen Type Describes the specimen type needed for testing


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.

Sequential maternal screening is a 2-part test that includes a first-trimester sample (SEQU / Sequential Maternal Screening, Part 1, Serum) and a second-trimester sample (SEQF / Sequential Maternal Screening, Part 2, Serum). Do not order this test unless you have already ordered test SEQU / Sequential Maternal Screening, Part 1, Serum. If a standalone second-trimester screen is desired, order QUAD / Quad Screen (Second Trimester) Maternal, Serum.


Draw blood between 15 weeks, 0 days and 22 weeks, 6 days. Do not draw blood after performing amniocentesis, as that may lead to an artificially increased serum alpha-fetoprotein level and unreliable results.



Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 1 mL

Collection Instructions: Spin down immediately.

Additional Information: Draw date is required.

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.

0.5 mL

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


Mild OK; Gross reject


Mild OK; Gross OK





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
SerumRefrigerated (preferred)7 days
 Frozen 90 days