Detection of Human Purine Nucleoside Phosphorylase/PNP by Western Blot. Western blot shows lysates of MCF-7 human breast cancer cell line, MDA-MB-231 human breast cancer cell line, K562 human chronic myelogenous leukemia cell line, LNCaP human prostate cancer cell line, HT-29 human colon adenocarcinoma cell line, and HT1080 human fibrosarcoma cell line. PVDF membrane was probed with 1ug/ml of Sheep Human Purine Nucleoside Phosphorylase/PNP Antigen Affinity-purified Polyclonal Antibody followed by HRP-conjugated Sheep IgG Secondary Antibody. A specific band was detected for Purine Nucleoside Phosphorylase/PNP at approximately 32kD. This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 1.