Dimer and related proteins in HGH

[readalot]

Just to absolutely clarify, your "dimer" number on reports describes all DPn greater than 1 as per USP document attached?

USP Monographs: Somatropin

See section Limit of high MW proteins -

Confirmed yes. Thanks @janoshik.

Post in thread 'Janoshik Analytical laboratory testing services'

Feb 28, 2025

>dimer" value on your test reports are all "aggregates (DP2-DPn)" of GH larger than monomer?


Yep.

• janoshik

 

[janoshik]

Confirmed yes. Thanks @janoshik.

Post in thread 'Janoshik Analytical laboratory testing services'

Feb 28, 2025

>dimer" value on your test reports are all "aggregates (DP2-DPn)" of GH larger than monomer?


Yep.

• janoshik

We chose dimer and related instead of the pharmacopoeial higher molecular mass proteins either because it either cleared some misunderstandings or fit into the reports easier. I'm not sure which one it was frankly.

 

[readalot]

We chose dimer and related instead of the pharmacopoeial higher molecular mass proteins either because it either cleared some misunderstandings or fit into the reports easier. I'm not sure which one it was frankly.

Good you gave everyone the secret decoder ring, haha. Thanks!

I just wanted to confirm and caution members to avoid using the term "dimer" to describe the result you are providing.

 

[AlexDavis43]

We chose dimer and related instead of the pharmacopoeial higher molecular mass proteins either because it either cleared some misunderstandings or fit into the reports easier. I'm not sure which one it was frankly.

People can't even get "dimer" right (dimmer lol).

And I'm sure they don't know it means 2 (could just as easily mean "10" like a dime, not realizing the one after dimer is trimer).

So maybe we can keep calling it dimer (or dimmer) and take comfort knowing in this context, it means "more than one" (or more simply, aggregates) since that's what we're getting with this assay (please correct me if I'm wrong on that last part).

 

[readalot]

and take comfort knowing in this context, it means "more than one" (or more simply, aggregates) since that's what we're getting with this assay

Yes, we are getting all DPn where n > 1 or hGH aggregates as you state (DP2, DP3, DP4, ..., etc.)

More info:

R

Post in thread 'Janoshik Analytical laboratory testing services'

Feb 28, 2025

yes, but I scratched what I don't really understand/doesn't make sense

Hi Jano,

So the reported "dimer" value for GH testing includes all DPn greater than DP1 (monomer)? Hence "dimer" on report is DP2, DP3, etc picked up by SEC?

TLDR: "dimer" value on your test reports are all "aggregates (DP2-DPn)" of GH larger than monomer?

Thank you.

For example:

Fig. 5 of attached.

https://www.agilent.com/cs/library/applications/application-sec-small-theraputic-proteins-advancebio-sec-5994-1829en-agilent.pdf

Figure 5 shows
the size-exclusion chromatogram of
somatropin carried...

• readalot