I haven’t had an answer so far from my colleagues. I try to answer to the best of my knowledge what I currently know.
Regarding the whole topic “nucleotides” there are still many question marks in the market, especially there is actually no official and standardized method to analyze nucleotides. That means that different labs/manufacturers may use different methods and may analyze different types of “nucleotides”.
So, I can only tell you what we at Leiber do here and try to establish.
- What we mean by the term „nucleic acid protein in CP“ is indeed the content of RNA + DNA (most of it actually is RNA, the DNA is constant and neglectable) in crude protein. Of course, this includes all the nucleotides, nucleosides, bases.
(strictly and scientifically speaking RNA and DNA don’t contain/are not protein, but they contain nitrogen)
- So far, we haven’t analyzed it routinely and regularly in our products by external labs as this is very expensive. But our R&D is still working on establishing a standardized method to analyze it in-house.
Their statement at the moment is that they want to establish this by the end of the year, then they are able to say more. What they do is measuring one of the (ribo-) nucleotides, the 2’ and 3’ GMP (guanosinmonophosphate) content by HPLC and based on that get the total ribonucleotides.
- Generally speaking, there are several different methods to measure RNA / (ribo-) nucleotides. Usually there is always a sample digestion (enzymatically, chemically or mechanically) necessary. Different digestions are for different measurements.
There are either direct or indirect (metabolic products) analyses of RNA. The most reliable results are considered to be obtained by indirect measurement with HPLC, CGE, CE and NMR methods.
HPLC is the apparently the most common one, and that is what our R&D wants to establish in-house as well (GMP, one of the metabolic products of RNA, is one of the ribonucleotides).
I hope this information is somewhat helpful at the moment. As soon as I get more info from our R&D I will inform you.
All the best,
Holger