For additional information about specimen collection, please visit MDHHS - Newborn Screening - Resources for Hospitals and Health Professionals
(michigan.gov) or contact the NBS Nurse Consultant at 517-335-1966.
Rev. 10/2021
Unsatisfactory Specimen:
Layered Sample
Layered Images (front and back of the same card):
Front of card: More than one drop of blood was applied to each circle.
Back of card: Layering prevented blood from evenly soaking through to back of card.
Satisfactory Specimen Image:
Both the front and back of the specimen card should look like the image above. Note the circles are filled and the even
saturation of a single blood drop applied to each circle.
Background:
• Layered specimens occur when more than
one drop of blood is applied to a circle or
blood is applied to both sides of the filter
paper.
• Layered specimens may cause test results
to be inaccurate.
A repeat specimen will be required.
This can lead to critical delays in
identifying serious health issues for the
infant.
Tips to Avoid Layered Samples:
• Avoid applying additional blood to a circle that is not filled.
Do not touch the same circle multiple times with blood.
• Do not apply blood to both sides of the filter paper.
• Avoid using capillary tubes for specimen collection.
If medically necessary, avoid devices containing heparin or
EDTA.
• Allow a large blood drop to form and lightly touch the drop
to the filter paper. Allow the drop to soak through and
completely fill the circle.
