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For most researchers, an ideal biologic is a single, uniformly
folded species to ensure that it will retain its activity and
behavior when it reaches the clinic. But it takes some time to
reach this point; it is unlikely you will have the perfect product
right from the start. As you go through the various stages of
development, your definition of what a high quality sample
looks like will vary. When you adjust parameters such as
buffers, storage time, or increase production scale, DLS is a tool
to help assess sample quality. Read more about the practical
considerations of designing a DLS experiment in Section 6.
Sample quality
Here, we show you how looking at the dispersity,
stability, and reproducibility of your biologics
preparations will tell you about sample quality. O en
when you observe a change in ACF fit from one sample
preparation to the next, the lack of reproducibility
reflects instability. We will explore this below.
You will already have looked at the r
H
, which gave
you some indication of how your biologic behaves.
It's important to understand this before you look at
the key parameter used to assess sample quality, the
polydispersity index, or PDI, which is also referred to
as simply the dispersity.
