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7.3.1. Managing non-linearity

Chapter 7

Binding Site recommend following the sample dilution protocol as shown in each product insert and reporting the first plausible result only. The use of non-standard sample dilutions, or skipping dilutions should be avoided. Examples of non-linear samples are shown in Table 7.4 and 7.5.

Dilution Result
(mg/L)
Sample A1/100 95.3
1/2000 202
Dilution Result
(mg/L)
Sample B1/100 145
1/2000 467

Table 7.4. Examples of non-linear κ Freelite results using a Siemens BNII analyser. The first plausible result should be reported (values in bold).

DilutionResult
(mg/L)
Sample A1/10>165
1/100>1650
1/1000790

Table 7.5. Example of non-linear λ Freelite results using a Binding Site SPAPLUS analyser. The first plausible result should be reported (value in bold).

It is important to note that Freelite results should not be interpreted in isolation and other laboratory findings and clinical symptoms should be considered when evaluating the status of the patient. In addition, the results from two consecutive measurements should be assessed when interpreting disease response [21].