Abstract: There is provided a combination of genetic markers capable of detecting minimal residual disease in neuroblastoma with high sensitivity, even in a sample with a low gene expression level. A reagent according to the present invention comprises a primer pair capable of amplifying each of genetic markers CRMP1, DBH, DDC, GAP43, ISL1, PHOX2B, and TH, by a nucleic acid amplification method, and is used for evaluating minimal residual disease in neuroblastoma. The reagent may further comprise a primer pair capable of amplifying the HPRT1 gene by the nucleic acid amplification method. A method of analyzing a biological specimen according to the present invention comprises the step of measuring an expression level of each of genetic markers CRMP1, DBH, DDC, GAP43, ISL1, PHOX2B, and TH in the biological specimen by a nucleic acid amplification method, using the above-described reagent. The nucleic acid amplification method is preferably performed by digital PCR.

Abstract: An aqueous solution of crude urokinase is contacted with a cross-linked diethylaminoethyl-agarose to have pyrogens adsorbed thereon. The effluent is then contacted with a water-insoluble, hydrophilic polysaccharide having a group of the formula:--CH.sub.2 CH(OH)CH.sub.2 Rwherein R is sulfothio, sulfo or p-sulfophenylamino, and the urokinase adsorbed is eluted from said polysaccharide. Pyrogen-free urokinase is thereby obtained in a high purity as the eluate.