In some cases it is possible to convert existing traditional PCR assays into Real-Time PCR assays, with a few considerations around primer design and master mix. Primer design is one of the first considerations for converting a traditional PCR assay. Real-Time PCR is most efficient with relatively short amplicon lengths, in the range of 50 to 150 bp. Longer products can be used if the cycling conditions are changed to accommodate longer extension times, but you should avoid products longer than 300 bp. In some cases it might be possible to design a TaqMan probe to hybridize between the two existing PCR primers. If not, you can use SYBR Green I for detection.
The master mix is another consideration when converting a traditional PCR assay into a Real-Time PCR assay. If a TaqMan probe can be designed, you might be able to use the same master mix that was used for the traditional PCR assay. If a TaqMan probe cannot be designed, you should add SYBR Green I to the master mix. In either case, a certain amount of optimization may be needed to obtain good Real-Time PCR results.