Peptide mass question

[greenwave1015]

Assume your friend mails you a tube labeled "1,000mg Reta powder". You know nothing about what's inside, whether it's sterile, whether it's grossly over/underfilled, etc. other than a "COA" that says 99.1% purity / 96.9% peptide assay. There are no vendor reviews. Maybe it's flour.

Assume you want to send a 10mg sample to a testing lab, using your mg scale, in your own vial.

Question is if you measured out exactly 10mg of this powder, should there be ~9.6mg of Reta present IF THE LABEL IS HONEST?

I can ask ChatGPT, but would like to hear what you have to say.

This is all a hypothetical scenario of course.

Thanks!

PS - regarding endotoxins, you're probably ok if you reconstitute with a filter (right?)

PSS- regarding sterility (vial, stopper, assembly tools, BAC water, etc.), no need for that discussion here

 

[woundcarping]

Assume you want to send a 10mg sample to a testing lab, using your mg scale, in your own vial.

Question is if you measured out exactly 10mg of this powder, should there be ~9.6mg of Reta present IF THE LABEL IS HONEST?

PS - regarding endotoxins, you're probably ok if you reconstitute with a filter (right?)

That’s not how any of that works.

 

[greenwave1015]

That’s not how any of that works.

Thanks dude.

 

[tcpnomad]

No - because the powder is mostly filler. 10mg of the powder will definitely not contain 10mg of reta.

One way to do it would be to weigh the entire amount of powder, and then take 100th of that weight. Because we know that the entire powder contains 1000mg of reta, therefore, 100th of that powder should contain 10mg of reta.

 

[unclebuff702]

Assume your friend mails you a tube labeled "1,000mg Reta powder". You know nothing about what's inside, whether it's sterile, whether it's grossly over/underfilled, etc. other than a "COA" that says 99.1% purity / 96.9% peptide assay. There are no vendor reviews. Maybe it's flour.

Assume you want to send a 10mg sample to a testing lab, using your mg scale, in your own vial.

Question is if you measured out exactly 10mg of this powder, should there be ~9.6mg of Reta present IF THE LABEL IS HONEST?

I can ask ChatGPT, but would like to hear what you have to say.

This is all a hypothetical scenario of course.

Thanks!

PS - regarding endotoxins, you're probably ok if you reconstitute with a filter (right?)

PSS- regarding sterility (vial, stopper, assembly tools, BAC water, etc.), no need for that discussion here

Theoretically, on paper, the core math does indeed math (if you had pure Reta, which you don't unless you have raw API). Even then, the problem in real world application is that unless you have an exceptionally powerful and expensive scale, there will be a margin of error trying to weigh out 10mg that will skew the data. But your mathematical assumption is correct. Then, you have to figure out how to dissolve it, bulk it with filler, break it down, lyophilize it, and vial it. Again, I highly doubt you have pure API but just trying to answer the question. If you do have pure bulk, be careful dude lol.

The big issue here is endotoxins lol. (Assuming it's NOT pure API and you just have regular lyophilized Reta) Filtering with a standard filter (.22 microns) will do absolutely nothing for endotoxins, which are around .01 microns in size. Filtering will filter out the majority of live bacteria/fungus if present... Endotoxins will slide right thru with zero shits given about your filter.

 

[tcpnomad]

Theoretically, on paper, the core math does indeed math. The problem in real world application is that unless you have an exceptionally powerful and expensive scale, there will be a margin of error trying to weight out 10mg that will skew the data. But your mathematical assumption is correct.

The big issue here is endotoxins lol. Filtering with a standard filter (.22 microns) will do absolutely nothing for endotoxins, which are around .01 microns in size. Filtering will filter out the majority of live bacteria/fungus if present... Endotoxins will slide right thru with zero shits given about your filter.

It's not just about accuracy. The powder actually contains a lot of filler material. Therefore, 10mg of powder will not contain 10mg of reta.

 

[unclebuff702]

It's not just about accuracy. The powder actually contains a lot of filler material. Therefore, 10mg of powder will not contain 10mg of reta.

Oh for sure, but he said the COA says Peptide Assay of 96.9%. Quantification assay means that 96.9% of the powder he has is pure Reta lol (which is super unlikely, but possible). If he has real, pure bulk API (with no filler, hence the 96.9% quantification assay), then yes the math, maths.

 

[Laxfinity]

Assume your friend mails you a tube labeled "1,000mg Reta powder". You know nothing about what's inside, whether it's sterile, whether it's grossly over/underfilled, etc. other than a "COA" that says 99.1% purity / 96.9% peptide assay. There are no vendor reviews. Maybe it's flour.

Assume you want to send a 10mg sample to a testing lab, using your mg scale, in your own vial.

Question is if you measured out exactly 10mg of this powder, should there be ~9.6mg of Reta present IF THE LABEL IS HONEST?

I can ask ChatGPT, but would like to hear what you have to say.

This is all a hypothetical scenario of course.

Thanks!

PS - regarding endotoxins, you're probably ok if you reconstitute with a filter (right?)

PSS- regarding sterility (vial, stopper, assembly tools, BAC water, etc.), no need for that discussion here

Throw it out and get something that is actually tested by a reputable lab with a COA

 

[woundcarping]

JFC, weighing the powder assumes it’s homogenous, which is no guarantee.

Even then, the problem in real world application is that unless you have an exceptionally powerful and expensive scale, there will be a margin of error trying to weight out 10mg that will skew the data.

The big issue here is endotoxins lol. Filtering with a standard filter (.22 microns) will do absolutely nothing for endotoxins…

This is correct on both accounts. The scale used to measure peptides would never be a “mg scale.”

It reads like the OP isn’t wanting to send a regular vial to test…. hundreds of dollars of testing but doesn’t want to waste a >$30 vial of Reta.

 

[Skidude]

The vast majority of what is visible in your vial is not Reta-

Real world example an R10 and an R30 vial will look the same, the 10/1000th of a gram (10mg) will be invisible to the eye.

When you mix in 2 ml of BAC you will end up with almost 2 ml of mix, it does not add much volume either.

you will need to send a vial in for testing.

Here is a great video from Jano, worth your time..