The sensitivity of the IC test strip for detecting -globin chains was 25 g/mL (Fig 3A). samples are first evaluated by MCV, MCH and Hb typing. Samples with high MCV and MCH values are excluded for the presence of the 0-thalassemia gene. Samples with low MCV or MCH values are assayed using the developed IC strip tests, where only samples testing positive are further assayed for 0-thalassemia by PCR. Patients with Hb H, EA Barts or EF Barts diseases do not need to use this IC strip assay. Thus, in this study, a simple and cost effective 0-thalassemia point of care test was developed. Introduction -Thalassemia is a genetic disorder caused by a defect in the -globin gene [1, 2], the severe form of which (0-thalassemia) is characterized by the deletion of both pairs of linked -globin genes, whereas a single -gene deletion is present in individuals with +-thalassemia. Accordingly, couples who carry the 0-thalassemia trait have a 25% risk of hemoglobin (Hb) Barts hydrops fetalis in each pregnancy due to the absence of -globin genes [3C5]. Hb Barts hydrops fetalis is the most severe type of thalassemia and causes fetuses die in utero. Their mothers also often suffer from several obstetric complications and must cope with the psychological burden of carrying a nonviable fetus to term [6, 7]. Currently, new cases of Hb Barts disease still occur and need to be prevented [2, 8]. Providing appropriate genetics counselling to individuals identified -thalassemia can prevent severe thalassemia disease and reduce the spread of the -thalassemia gene [9C12]. Polymerase chain reaction (PCR) is currently the most commonly used technique to diagnose 0-thalassemia [13C16]. However, this technique is not widely employed in routine laboratories of rural hospitals in resource-limited countries. Thus, the development of more cost effective and simplified techniques for identifying 0-thalassemia carriers are greatly needed for incorporation into the routine thalassemia screening programs of health promotion policies. In Southeast Asian countries, the Southeast Asian (SEA) deletion (–SEA) is the most common 0-thalassemia genotype [2, 8, 11, 17, 18]. The minute amounts of Hb Barts and -globin chains in red blood cells (RBCs) are TPT-260 especially observable in 0-thalassemia subjects, including those with 0-thalassemia (–SEA) [19C24]. Using a monoclonal antibody (mAb) generated in our lab, we previously developed an immunochromatographic (IC) strip test for detecting Hb Barts in RBC hemolysates [21, 25C27]. In TPT-260 this study, using a panel of our generated anti–globin chain mAbs [28], we established another IC strip test that can detect -globin chains in RBC lysates. The IC strips for Hb Barts and -globin chain detection were affirmed for their potential use in 0-thalassemia differentiation, especially in 0-thalassemia (–SEA) carriers. The clinical sensitivity, clinical specificity, positive predictive value TPT-260 (PPV) and negative predictive value (NPV) of both IC strip tests were validated, and a new 0-thalassemia screening strategy was also proposed. Materials and methods Antibodies and reagents The anti–globin chain mAbs PL2 (IgG1 isotype) CD350 and PL3 (IgG1) [28] and the mouse anti-Ag85B mAb clone AM85B-8B (IgG1) [29] were generated in our laboratory. Goat anti-mouse IgG antibody was obtained from Jackson ImmunoResearch (West Grove, PA, USA). EZ-Link? Sulfo-NHS-LC-Biotin was purchased from Pierce (Rockford, IL, USA). Horseradish peroxidase (HRP)-labeled streptavidin and 3,3,5,5-tetramethylbenzidine (TMB) substrate were purchased from Invitrogen (Camarillo, CA, USA). Goat anti-mouse immunoglobulins antibody was obtained from KPL (Gaithersburg, MD, USA). The IC strip test for the determination of Hb Barts in RBC hemolysates was purchased from i+Med Laboratories Co., Ltd. (Bangkok, Thailand). Identification of an anti–globin chain mAb pair for.