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the jano testing didnt look bad on qsc stuff tho...but i dont hold any water on lobster gh

"Purity" barely tells us anything about the GH other than it's the correct sequence of amino acids.

The structure is vital to how rHGH works. Getting the folding right is the most difficult part of manufacturing and we have no idea how one batch compares to another. Worse is that the UGLs know this too.

Pharma must test for correct structure before a batch is approved.

Our testing can't distinguish between the inactive unfolded rHGH on the left or the correct molecule on the right.

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Just chilling seeing everyone getting mad about their orders.
I stocked before qsc went down.
Now I am waiting to see if this vendor will ever sort their shipping, they seem overwhelmed I will keep waiting.
If I am on emergency I'll use the pricey eu vendor, at least I got my stuff in 2 weeks from first contact to my door.
But I hope they fix their shit, especially as last time I read lobster was going 40 days on holidays...
 
Just chilling seeing everyone getting mad about their orders.
I stocked before qsc went down.
Now I am waiting to see if this vendor will ever sort their shipping, they seem overwhelmed I will keep waiting.
If I am on emergency I'll use the pricey eu vendor, at least I got my stuff in 2 weeks from first contact to my door.
But I hope they fix their shit, especially as last time I read lobster was going 40 days on holidays...
it seems to be really mixed. My order went well. JY pharma is also an option
 
"Purity" barely tells us anything about the GH other than it's the correct sequence of amino acids.

The structure is vital to how rHGH works. Getting the folding right is the most difficult part of manufacturing and we have no idea how one batch compares to another. Worse is that the UGLs know this too.

Pharma must test for correct structure before a batch is approved.

Our testing can't distinguish between the inactive unfolded rHGH on the left or the correct molecule on the right.

View attachment 329505
Curious if @janoshik even offers a way to check this for us

Chatgpt:
Yes, there are several analytical methods used to determine whether recombinant human growth hormone (rhGH) is properly folded. These methods assess secondary and tertiary structure, disulfide bonding, aggregation, and bioactivity. Here are the key techniques:

1. Circular Dichroism (CD) Spectroscopy

  • Purpose: Assesses secondary structure (alpha-helices, beta-sheets).
  • Use for rhGH: rhGH has a high alpha-helical content; CD can confirm whether the folding pattern matches the expected helical structure.
  • Pro: Quick and non-destructive.
  • Con: Requires purified protein.

2. Fourier Transform Infrared Spectroscopy (FTIR)

  • Purpose: Evaluates secondary structure using absorbance in the amide I and II regions.
  • Use for rhGH: Confirms alpha-helix vs beta-sheet content.

3. Intrinsic Fluorescence Spectroscopy

  • Purpose: Measures tertiary structure based on tryptophan environment.
  • Use for rhGH: Changes in fluorescence suggest misfolding or unfolding.

4. Differential Scanning Calorimetry (DSC)

  • Purpose: Measures thermal stability and unfolding transitions.
  • Use for rhGH: Misfolded protein often has altered melting temperatures or shows no clear thermal transitions.

5. Size-Exclusion Chromatography (SEC-HPLC)

  • Purpose: Detects aggregates and ensures monomeric rhGH purity.
  • Use for rhGH: Aggregation often suggests misfolding.

6. SDS-PAGE (with/without reducing agents)

  • Purpose: Confirms correct molecular weight and disulfide bonding.
  • Use for rhGH: Disulfide bonds are essential for GH structure; non-reducing conditions reveal improper cross-linking.

7. Mass Spectrometry (MS)

  • Purpose: Confirms exact molecular weight and can assess disulfide bond pairing (when paired with digestion + mapping).
  • Use for rhGH: Ensures no truncations or unexpected modifications.

8. Nuclear Magnetic Resonance (NMR) or X-ray Crystallography

  • Purpose: Gold-standard structural analysis.
  • Use for rhGH: Mostly used in research, not routine QC, due to cost and complexity.

9. Bioassays / Cell-based Functional Assays

  • Purpose: Confirms biological activity, typically by measuring IGF-1 production or GH receptor activation.
  • Use for rhGH: The most functionally relevant test — if the protein is folded wrong, it won’t activate the receptor effectively.

Summary Table:​

MethodWhat It TestsGood For
CD SpectroscopySecondary structureQuick screening
FTIRSecondary structureComplement to CD
Fluorescence SpectroscopyTertiary structureFolding status
DSCThermal stabilityMisfold detection
SEC-HPLCAggregates vs monomersPurity check
SDS-PAGEMW, disulfide patternReducing vs non-reducing test
Mass SpectrometryMW, disulfide mappingHigh resolution
NMR / X-rayAtomic-level structureResearch grade
Cell-based BioassaysFunctional folding and receptor activityFinal confirmation

If you're working with a specific batch or supplier and want to evaluate folding quality, I can help design a testing panel based on what's available to you.
 
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