Commercially available estrone-sulfate seems to contain some sort of stabilizer, e.g. app. 35% Tris (the Sigma product). Thus, with this product it is impossible to prepare a calibration curve for use with quantification of endogenous estrone sulfate in serum because you do not know how much is estrone-sulfate and how much is Tris after weighing. I have been able to find estrone-sulfate without stabilizers but then the SO4-group seems to come off - which is also not great... Any experience with obtaining stable estrone-sulfate or dealing with estrone-sulfate containing stabilizers for quantitative analysis?
Hi Tue
Yes you have to used stabilized Estrone-SO4. You can assume that 65% w/w is E1-S. We already tested and proportion were good. You can ask or do RMN spectrum to verified proportion or deconjugated ans compare to estrone standard. In methanol solution (at -20°C) this compounds is stable at least a year.
Yes, the unstabilised Estrone sulphate can dissociate in the analytical instrument like GC during quantification due to thermal instability. The stabilised form is the better option. The assay report by the supplier could be relied upon but there is need to confirm by use of stock estrone as standard.
Thank you for your answers. I was just informed by Sigma that certificates stating the exact amount of Tris for each lot of their E1-S products are available on their website.
- Badges
- Science method
- Similar topics
- Chemistry
- General Biochemistry
- Biochemical Techniques
- Analytical Chemistry