In the article entitled The Thyroid in Children: II. In Vitro Erythrocyte Uptake of Radioactive L-Triiodothyronine, by Kunstadter, et al. (Pediatrics, 30:27, 1962, Dr. Marks (Pediatrics, 30:1012) noted an error in test dosage. The authors advise that the dosage given under Methods (p. 28) should be ". . . to contain 10-120 x 10-4 mg/0.1 ml, with 100-400 x 102 counts/minute/0.1 ml, and stored, etc."