Table 1.

Primers and conditions for the two-tiered PCR method to prepare a pool of pathway-specific probes and use them to survey strains for biosynthetic potential of the targeted class of natural products

natural product class	pathway- specific probe	primera	1stround PCR	2nd round PCR	hybridization temperature (° C)
reduced	type I PKS	5′-ATGTAGTGAGCTGCTTCGGCGATGGACCCGCAGCAGCG-3′	95 °C/30 s	95 °C/30 s	55
polyketides		5′-AATCAGCATCCTTCGACCGCGCCGTCCTGGTTSACSGC-3′	60 ° C/1 min	48 ° C/30 s
			72 ° C/40 s	72 ° C/40 s
aromatic	type II PKS	5′-ATGTAGTGAGCTGCTTCGGGCAGCGGITTCGGCGGITTCCAG-3′	95 °C/30 s	95 °C/30 s	55
polyketides		5′-AATCAGCATCCTTCGACCCGITGTTIACIGCGTAGAACCAGGCG-3′	65 ° C/1 min	48 ° C/30 s
			72 ° C/30 s	72 ° C/30 s
			10 cycles	35 cycles
nonribosomal	NRPS	5′-ATGTAGTGAGCTGCTTCGACCTCSGGCWCCACCGGC-3′	95 °C/30 s	95 °C/30 s	57
peptides		5′-AATCAGCATCCTTCGACCGCCGSIGATCTTSACCTG-3′	65 ° C/1 min	48 ° C/30 s
			72 ° C/50 s	72 ° C/50 s
			10 cycles	35 cycles
diterpenoids	DTS	5′-ATGTAGTGAGCTGCTTCGACGCTCAGTGCGGTSGAG-3′	95 °C/30 s	95 °C/30 s	58
		5′-AATCAGCATCCTTCGACCGGIGAGGCGTGCCACTTGTC-3′	65 ° C/1 min	48 ° C/30 s
			72 °C/1 min	72 °C/1 min
			10 cycles	35 cycles

^aThe designer primers consisted of the pathway-specific sequences and the unbiased AT-rich tag (underlined). S, C/G; W, A/T; I, inosine.