| As an avian clinician
you're probably well aware of the harmful effects of zinc ingestion by birds,
and the sometimes tedious task of tracking down the source, be it cage wire,
bird toys, keys, or, paints, skin preparations, or even suppositories formulated
with zinc. Needless to say, sample handling techniques that disqualify or
greatly mask the accuracy of serum zinc diagnostic testing is just not acceptable.
There is some belief that certain media used for serum transport can cause
artifactual effects on zinc testing. Even some clay brands used in filling
hematocrit tubes was thought to adversely affect zinc levels. Many laboratories
may, in the face of questionable zinc results, introduce these possible
contributors, and then partially dismiss the results. We've been tracking
the zinc testing going on in our facility and with the help of Dr. Jowett
at Louisiana State University, we've decided in our desire to maximize the
accuracy of our zinc diagnostics, some investigation into what would be
the best choices of media to use is in order. Here's what we came up with:
We've looked into several cases, but these three best demonstrated the trends
we've been seeing. Below are comparisons of sample suspension using plain
(no anticoagulant) serum tubes, Sarsted brand tubes, and hematocrit tubes
using Critoseal clay. |
