Patent DE-10011163-A1 (DE)
Title: System for detection of albumin transport properties, induces targeted conformation changes in samples for electron spin resonance spectrometry for accurate early warning of changes in the patient or product
Inventor: MURAVSKY VLADIMIR A
IPC: G01N33/68
Filed: 2000-02-28
Abstract: Detection of the transport properties of albumin in a sample containing albumin using electron spin resonance (ESR) spectroscopy, by inducing the albumin molecules into a targeted conformation change is new.  Detection of the transport properties of albumin in a sample containing albumin using electron spin resonance (ESR) spectroscopy, by inducing the albumin molecules into a targeted conformation change,  where aliquot portions have at least three different concentrations of a spin probe bonding with the albumin and, additionally, at least three different concentrations of a polar reagent. A computer simulation of the ESR uses the ESR spectra with the spin probes and reagent to give the degree of change in the bonding parameter of the spin probe at the albumin bonding points, according to the spin probe concentration and the reagent concentration. The changes in the transport characteristics of the albumin are computed from the parameter value changes. The added spin probe concentrations are selected so that the mean ratio of the spin probe concentration to the albumin concentration is 2.5 \!0.5. From the mean value, at least three additional concentrations are selected where the deviation from the mean value is  >= 1.0. The concentration of the polar reagent is selected so that the final concentration of the reagent is (0.6 \!0.25)\*Cp (where Cp is the critical concentration of the polar reagent and a breach of it would lead to denaturing of the albumin). Leading from the mean value, at least two additional reagent concentrations are selected with a minimum deviation of 15% from the mean value to be added to the spin probe and the polar reagent of each aliquot portion within the concentration range so that , in at least one aliquot portion, there is a low spin probe and polar reagent concentration, in at least one aliquot portion there is a medium spin probe and reagent concentration, and there is a high spin probe and reagent concentration in at least one aliquot portion.  Independent claims are also included for: (1) a test kit with a plastics plate fitted with a number of cavities, and preferably a microtitration plate. The cavities contain fixed, stabilized and accurately dosed concentrations of a spin probe and polar reagent; (2) an ESR spectrometer with a shrouded compact electromagnet with a Hall stabilizing system (2), and a measurement resonator (3). An ultra high frequency (UHF) unit (5) with a controlled main oscillator gives a frequency tuning in an initial range of 200-400 MHz coupled with the central frequency of 9.45 GHz \!0.5 GHz.. It has an apparatus control and signal register (9) and a thermostat control (7) for the test samples. The measurement resonator (3) is coupled to an additional control to tune the resonance frequency in a second range of 10-50 MHz, using a variation of the hollow resonator volumes, as a compensation for the frequency difference on registering the spectra of the aliquots; and (3) a method to achieve a high accuracy, stability and sensitivity at the ESR spectrometer. The registered ESR signal data are processed at the signal register unit (9) where there is computer simulation. A digital filter takes out signal noise and pulse interference to reduce the extracted ESR signals. The computation of each spectrum point is through a special algorithm using (N) records of the ESR signals (Si) accumulated for each spectrum point, added with special weighting factors (ki). The weighting factors are in an inverse proportion to the squares of the measurement faults of the corresponding records using 2 defined formulae.