Beta Thalassemis is best diagnosed by?

Hemoglobin electrophoresis performed after 6-12 months of age is usually diagnostic when levels of hemoglobin A2, hemoglobin F, or both are elevated. Thalassemia Syndrome **-Globin Genes Hb A Hb A2 Hb F Normal Homozygous 97-99% 1-3% < 1% Thalassemia major Homozygous 0 0% 4-10% 90-96% Thalassemia major Homozygous + 0-10% 4-10% 90-96% Thalassemia intermedia Homozygous + (mild) 0-30% 0-10% 6-100% Thalassemia minor Heterozygous 0 80-95% 4-8% 1-5% Heterozygous + 80-95% 4-8% 1-5% Ref: Kligman, Behrman, Jenson, Stanton (2008),Chapter 462, "Hemoglobinopathies", In the book, "Nelson's Textbook of Pediatrics", Volume 2, 18th Edition, New Delhi, Page 2035; Harrison's Internal Medicine, 16th Edition, Page 599, 608; CMDT, 2005, Page 466