Keywords: control survey, radioimmunoassay, adrenocorticotropic hormone, growth hormone, somatomedin C, follicle stimulating hormone, luteinizing hormone, prolactin, thyroid stimulating hormone, triiodothyronine, free triiodothyronine, thyroxine, free thyroxine, triiodothyronine uptake, thyroglobulin, thyroxine binding globulin, parathyroid hormone, calcitonin, insulin, C-peptide, glucagon, gastrin, testosterone, free testosterone, estradiol, progesterone, 17α-hydroxyprogesterone, aldosterone, cortisol, renin, immunoglobulin E, digoxin, α-fetoprotein, cartinoembryonic antigen, tissue polypeptide antigen, CA125, CA19-9, CA15-3, prostatic acid phosphatase, β₂-microglobulin, ferritin