RT-PCR of mRNA isolated from spleen erythropoietic cells. Total RNA was isolated from the spleens of normal and band 3 null mice as described in Materials and Methods. cDNA was synthesized using random hexamer primers and M-MLV reverse transcriptase. Specific GPA primers were used to amplify a small fragment of the GPA cDNA. Small segments of band 3 and β globin cDNA were also amplified as negative and positive controls, respectively. The results confirm the presence of GPA mRNA indicating that the transcription of the gene takes place in band 3 −/− erythroblasts.