2 results about "International unit" patented technology

The invention discloses an on-line separation and valuing method for free thyroxine in serum. The method comprises the following steps: (1) setting a two-dimensional liquid chromatogram; (2) on-line separation and removal of macromolecular interferents in the serum; (3) retaining free thyroid hormone; (4) on-line separation of free thyroid hormone; (5) on-line valuing by isotope dilution mass spectrometry; and (6) cleaning the two-dimensional liquid chromatography system. The method provided by the invention realizes on-line separation of free thyroid hormone in serum and absolute constant value. A first-dimensional chromatographic mobile phase is a mild ammonium salt buffer solution and does not contain an organic solvent, so that thyroid hormones combined with protein in serum can be kept in a combined state, and a target object entering mass spectrometry is free thyroid hormones; and the valuing result can be traced to the international unit system through the national certified standard substance. Compared with traditional serum off-line treatment modes such as solid-phase extraction and equilibrium dialysis, the method has the characteristics of high efficiency, reliability and easiness in operation.

The present application relates to the technical field of biometrics and in vitro diagnosis standardization, and particularly relates to a preparation and value determination method of alpha-synuclein solution standard substance, comprising the following steps: cloning a gene coding alpha-synuclein into a prokaryotic expression vector for recombinant expression, purifying the protein raw material with purity greater than or equal to 99% through affinity chromatography and ion exchange chromatography; diluting and sub-packaging the protein raw material for storage to obtain the solution standard substance; determining the value of the standard substance by using an isotope dilution mass spectrometry method based on amino acid analysis, calculating the mass concentration value by measuring the peak area ratio of stable amino acids and isotope-labeled amino acids after hydrolysis, and tracing the value to the international unit system through the amino acid primary standard substance; and performing uniformity testing and stability investigation on the standard substance, solving the problem of lack of standard substance with metrological traceability in the alpha-synuclein detection field, and obtaining the standard substance which can be used for value transmission and detection result standardization among different in vitro diagnosis platforms.