Luminex multiplex bioassay makes it
possible to analyze multiple analytes in a single reaction. This makes it possible to get more data from
a small sample volume. Luminex assay also need a shorter timeframe than
conventional immunoassay methods.
Much
of this is made possible by the use of microspheres or the color-coded beads
used with this system. The underlying xMap technology forms a key element that
allows these beads to quantitate and run multiple analytes. This underlying
technology is used in several systems, including Bio-Rad's Bio-Plex multiplex
system. Therefore, you can as easily use a bioplex assay to handle your
immunoassay requirements.
There
are some considerations to be made and steps to be followed. Here are the key
steps that aid Luminex Bioplex studies in drug development.
Proper Sample
Preparation Defines Luminex Bioplex Studies
Sample
preparation with attention to detail will define the results of any study. An
error in sample preparation can be magnified throughout the study and give
unwieldy results that can upend studies.
Consistency
is important. Choose a single sample type for your study. For example, while
plasma and serum are both commonly used for immunoassays, their use in samples
should not be interchangeable. Plasma has 3-4% more protein than serum.
Additionally, plasma and serum are processed differently.
Sample
matrices are different for each type. It is best to consider any time and
temperature requirements as well. Many biomarkers can degrade at room temperature.
In such situations, consider using a cooled centrifuge or keeping your sample
on ice or using the freezer.
Adopt
a well-strategized storage protocol that does not risk damaging the sample. A
sample should be stored at a consistent temperature and not be subject to
changes like freeze-thaw cycles.
Filtering the
Sample Is Necessary
Filtering
the sample can be seen as a part of sample preparation. However, it is
important enough for multiplex systems to be mentioned separately.
Miniaturization is what makes these multiplex assays tick. It is also what
makes filtration necessary.
The
microspheres used are 5.6 µm in diameter. The presence of impurities like
particulates of that size is possible. These particulates can then interfere
with the signal and affect the results. This is one of the reasons creating
samples for the Luminex platform is considered “complex”.
Check to see
that the Sample Volume is Adequate
A
Luminex Bioplex system uses a much lower sample volume than conventional
immunoassay methods like ELISA. But there still is a minimum sample volume
necessary. Availability and sample volume can be low, especially in the early
stages of drug development. It pays to be careful about the available sample
volume and ensuring you have enough for the multiplex immunoassay.
Keep Relevant
Software Updated
Luminex Bioplex systems use software to manage the process
and show the results. This makes the result easy to understand and manage.
Since the software is so important, it is necessary to keep it updated to the
latest version. Of course, software updates don’t flow out regularly, like some
mobile apps. Even so, do periodic checks on the software.
Conduct a
Pilot Study
There
are times when you can't be sure that the Luminex assay will respond
well to the method or protocols. In such cases, it is better to run a pilot
study. Also, remember that though these kits are cost-effective for analysis,
they are also individually expensive. It is better to be careful with the
decision-making and management of the study.
