The method for measuring testosterone is being switched from immunoassay to liquid chromatography tandem mass spec and I am establishing a new reference range for both sexes as well as the free androgen index
to find the right control matrix
Utility, Limitations, and Pitfalls in Measuring Testosterone: An Endocrine Society, Positional Statement.
Comparison of measurement of Testosterone by various methods advantages and disadvantages are illustrated.
http://press.endocrine.org/doi/pdf/10.1210/jc.2006-1864
I was referring to LC-MS/MS because it is known that for ELISAs the result depends on the manufacturer
03 April 2015 7,034 2 View
I am using a 2707 waters HPLC device. When I try to inject a sample, it says missing plate or rack. I changed the needle and calibrated its position but I still get the same problem. I even get...
02 March 2021 1,408 1 View
Hello! I'll do a size exclusion chromatography, but I only have an open column, and I'll perform the peptide extraction from yeast, using buffer lysis (sodium phosphate 50 mM/NaCl 30 mM/DNAse and...
01 March 2021 2,215 2 View
Hi, I am running a size exclusion chromatography experiment with a buffer containing Potassium Acetate as a salt. I analyse these fractions through SDS-PAGE. After boiling my SEC fractions in...
01 March 2021 2,622 3 View
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24 February 2021 1,365 3 View
Hi, I am a chemistry undergraduate doing my dissertation project on HPLC. In my project, I need to predict the HPLC retention time of 20 aromatic molecules, the calibration set. To do this I will...
24 February 2021 2,602 1 View
Looking for method of extracting and analyzing vitamin D in foods by HPLC
24 February 2021 7,524 7 View
To do liquid biopsy and look for specific gene expressions there are so many published papers. Thera are different protocols and procedures used to isolate circulating cell free RNA or mRNA from...
23 February 2021 7,326 5 View
What HPLC Marker(s) or standard is used to detect and quantify anthocyanins such as Delphinidin, Cyanidin in a given sample of plant extract?
23 February 2021 1,832 4 View
My baseline increases without any explanation, it is only fixed by changing the solution B, will it be the column? Reagents? Bomb? Detector? Solution A: H3PO4 0.01% IN WATER Solution B: H3PO4...
21 February 2021 5,656 3 View