Quantitative evaluation of anti-HBs in sera--II

We have investigated about the most correct way to express the anti-HBs titration in serum. The following linear regression has been elaborated on the basis of the results (converted into logarithms) obtained by 33 titrations of the International Reference Standard (the dilutions prepared were the following: 150, 100, 75, 37.5, 18.75, 9.375 mUI/ml) by as many kit lots AUSAB EIA (Abbott): y = 0.8590732x - 1.6936435. The correlation between the couples: optical density log. mUI/ml has been highly significative (r = 0.991091; P less than 0.01). In order to limit the variability effects in the same laboratory, the use of the correction factor "F" is suggested. The variation of the optical density corrected by the "F" variation is illustrated. A linear regression on the Author's data has been elaborated by the inverse application of the Hollinger formula. The adaptability of this linear regression has been tested on 196 dilutions out of the 33 standard tests studied. The average values obtained, the 95% confidence limits and the mean values +/- 2s limits are compared with the same values obtained by applying the Hollinger original formula.