An official website of the United States government
Here's how you know
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Effect of sample volume, punch location and compression of the sample on DBS phenylalanine concentrations in a patient with phenylketonuria (PKU) (results are a mean of n = 3). C, central punch; P, peripheral punch; Comp, compressed.