Putrescine, spermidine, and spermine levels during somatic embryogenesis of interior spruce (Picea glauca x Picea engelmannii complex) were quantified On abscisic acid supplemented growth medium putrescine and spermidine levels increased two-fold coinciding with maturation of the early somatic embryos to globular embryos. Polyclonal antibodies raised against Escherichia coli arginine decarboxylase (ADC) and ornithine decarboxylase (ODC), following affinity purification specifically recognized spruce ADC and ODC, which corresponded to 85kD and 65kD bands on western blots of total protein extracts from embryogenic masses, Immunoassays using these antibodies showed increased ADC levels corresponding to embryo maturation while ODC levels remained the same. From these results it is concluded that polyamines are involved in the maturation of somatic embryos of interior spruce.