**10. Pitfalls in laboratory diagnosis of β-thalassemia and HbE**

There are several pitfalls to be concerned when using laboratory data in diagnosis of β-thalassemia and HbE. The pitfalls are in both screening and confirmatory steps of laboratory diagnosis.

HbE tube test relies on concentration of NaCl. Therefore, exact amount of NaCl in the reagent must be prepared following the suggested ingredient. False positive results will be obtained if NaCl concentration is too high, and *vice versa.*

HbE screen test relies on pH-based microcolumn chromatography. Therefore, exact pH of buffer in the test kit must also be prepared. Too high pH causes falsely negative results and *vice versa.*
