A method of calibrating a device for measuring the concentration of creatinine using one or more calibration solutions, the method comprising: receiving concentrations at an initial time of creatine, Cr, and/or creatinine, Crn, of the one or more calibration solutions; receiving outputs of the measuring device at the end time; calculating the concentration of Cr and/or Crn in the calibration solutions at an end time using a temperature model, wherein the temperature model indicates changes in temperature of the calibration solutions from the initial time to the end time; and determining a relationship between the outputs of the measuring device and the calculated concentrations of Cr and/or Crn.

The present invention relates to a diagnostic strip for an enzymatic test for determining the amount of sarcosine and creatinine based on the formed hydrogen peroxide in a biological sample or in an environmental sample with visual or electronic evaluation of intensity of the colour product. The diagnostic strip consists of a pad to which zones of an absorbent matrix are applied to conduct the test, consisting of sample zone (V) at one end of the strip followed by one or two reaction zones (R1), (R2), where to (R1) zone is applied reagent containing sodium salt of 3-(N-ethyl-3-methylaniline) propanesulfonic acid and to (R2) zone is applied reagent containing peroxidase and 4-amino-2,3-dimethyl-1-phenyl-3-pyrazole. Reaction zones are followed by detection zone (D) and beeswax zone (Z), forming the other end of diagnostic strip.

A method of calibrating a device for measuring the concentration of creatinine in a sample including one or more enzyme modulators, the device comprising an enzyme layer, the method comprising: determining sensitivities of the device for each of one or more calibration solutions; determining a degree of modulation for the sample to be measured, determining a degree of modulation for each calibration solution; wherein said determining of each of the degrees of modulation comprises estimating the concentration of an enzyme modulator in the enzyme layer of the device; and calculating the sensitivity of the device for the sample, wherein the said calculating comprises adjusting the sensitivity of the device for each calibration solution by a factor comprising the determined degrees of modulation of the sample and the calibration solution.

The present invention relates to a prostate screening module and the method for operating the same. It uses nanometer-grade nickel oxide as the screening film. By contacting nickel oxide with hydrogen peroxide having various concentrations, the surface potential of nickel oxide will be changed and resulting in voltage shift, which can be used to judge the concentration of hydrogen peroxide. The sample for screening is urine or blood serum. After the sarcosine in urine or blood serum is oxidized and forming hydrogen peroxide, the content of sarcosine in the sample can be deduced by means of the reaction between hydrogen peroxide and nickel oxide. Accordingly, the possibility of prostate cancer can be evaluated.

This invention relates to mutagenized redox oxidase enzymes used to design enzyme electrodes with improved interference characteristics in the presence of mediator and oxygen in the assay. This recombinant modified enzyme has enhanced capability to transfer electrons to redox mediator instead of its natural electron acceptors such as O.sub.2, NAD, NADP, etc., which will improve the assay performance with less interference and higher sensitivity.