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Evaluating the intensity distribution and identifying the
peak that corresponds with your monomer is crucial for
evaluating your biologic. What happens if you see an
increased PDI and multiple peaks in your sample and
you don't know where they are coming from? Are they
biological or inorganic particles? DLS will detect and
measure them all.
DLS assesses all particles in solution
First step: Rule out dust and dirt by making sure plates,
tubes, and tips are stored in an environment free of
these contaminants
Second step: Check whether your buffer contains larger
additives like sugars or PEGs. Assess whether these are
necessary for your biologic and identify which peak(s)
corresponds to the additive. Running DLS on the sample
buffer without your biologic will help determine if
certain peaks are from these additives.
Third step: Could it be that your sample contains
unconjugated particles or contaminating proteins?
Consider whether and how to clean up your sample to
remove these.
