Applications of the Large Mass Expansion

Errors in applying liquid sample are judged during biochemical analysis wherein a droplet of liquid sample is applied to an analysis medium containing a reagent, which chemically reacts with a specific constitutent in the liquid sample, the analysis medium is then incubated, the optical densities of the analysis medium are determined, and concentration of the specific constituent in the liquid sample is determined from the optical densities of the analysis medium thus determined. The method for judging errors in applying a liquid sample comprises the steps of determining the optical density of the analysis medium plural times with the passage of time while the analysis medium is being incubated, and calculating the difference between the maximum value and the minimum value of the optical densities thus determined for the analysis medium. The difference is compared with a predetermined threshold value. In cases the difference is smaller than the threshold value, it is judged that errors occurred in applying a liquid sample to the analysis medium.