RT-PCR analysis of mineral-associated gene expression of periodontal cells in PLGA scaffolds. RNA extracted from the implants was fractionated on 2% agarose gels and compared to corresponding β-actin to assess relative loading of RNA. Gene expression with the use of RT-PCR for Col-I, Col-XII, BSP, and OCN was noted in all cell implants, whereas OCN gene expression was seen only in OCCM/PLGA implants. This is a representative experiment, with similar results noted on two occasions. (Ethidium bromide staining.)