
Keywords: HEPES, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; IMAC, immobilized metal-ion affinity chromatography; MESG, 2-amino-6-mercapto-7-methylpurine ribonucleoside; PNP, purine nucleoside phosphorylase (EC 2.4.2.1)Soil phosphate determination in the fi