Chapter 9

The measuring ranges of HLC assays are dependent upon two factors: the slope of the respective calibration curve and the portion selected for the assay. The latter should be chosen to allow the maximum number of normal and abnormal clinical samples to be measured at the initial sample dilution.

Typical analytical ranges (at the standard dilution) on the Binding Site SPAPLUS® are shown in Table 9.1, and typical calibration curves are shown in Figure 9.8. Samples containing higher concentrations require further dilution. Samples containing lower concentrations can be re-assayed at a lower dilution (or neat on the SPAPLUS).
Specificity Dilution Approximate measuring range (g/L)
IgGκ1/20 1.9 – 40.0
IgGλ1/20 0.92 – 29.5
IgAκ1/10 0.18 – 11.2
IgAλ1/10 0.16 – 10.4
IgMκ1/10 0.20 – 5.00
IgMλ1/10 0.18 – 4.50

Table 9.1. Measuring ranges for HLC assays on the Binding Site SPAPLUS.

Calibration curves are validated by the measurement of high and low control samples. It is also recommended that all laboratories take part in external quality assurance schemes, to allow comparison of performance and results among different test sites (Chapter 38).