RT-PCR and Western blot results: TM3 cells express GAD67 and VGAT. RT-PCR experiments (A) revealed that TM3 cells possess mRNA for GAD67, but lack GAD65 (data not shown), as well as VGAT. Expected product sizes were 399 bp for GAD67 and 302 bp for VGAT. Western blot analysis (B) revealed the presence of GAD67 in TM3 cells. Protein probes from mouse brain served as positive control and depict immunoreactivity for both GAD isoforms.