A technique of “flame programming” using a refined vertical tube reactor (VTR) has been developed whereby widely separated preignition zones (cool and blue flames, and intermediate dark zones) can be studied and compared. In addition, the reactor is fitted with removable side arms for doping and/or spectroscopic studies. The use of the VTR gives nearly adiabatic, planar reaction zones for the preignition events. This new VTR responds very rapidly to changes in experimental parameters and achieves equilibrium within a few minutes. The flames are stable to within ±0.5 mm over an eight hour period with two stage ignition separations of over 40 cm. Reproducible and point source sampling of the flame zones can be made very precisely with reference to the location of the flames. The “free floating” flame stages show a minimum interaction with the walls and are extremely sensitive to additives.