An activation analysis procedure has been developed to determine manganese and copper serum values in one milliliter of serum or less rapidly and with good precision. The sample is irradiated in a neutron flux of 1012cm−2sec−1for two hours followed by nitric acid digestion. The activity plus carrier is absorbed from saturated lithium chloride solution on Dowexl-8 contained in a syringe. After washing the resin with more lithium chloride, the syringe is counted in a five inch well crystal multichannel spectrometer. The carrier is washed off the syringe by dilute acid and analyzed. The sample concentration is determined by comparison to irradiated standards correcting the unknown for decay and chemical yield.