Table 1

Primer^a	Position^b	Sequence
Hyd2F	811-829	5`-CCGG(C/T)TGCCCGCC(G/C)AACCC-3`
Hyd1F	1441-1467	5`-CGCGACGCCCAGCACTTCACCCAGCGC-3`
Hyd4F	1786-1815	5`-TTCACCAA(C/T)GCCTACTTCCT(G/C)GGCGGCCAC-3`
Hyd5F	1844-1879	5`-GCAGGGCTTCCAGGTAGTGGGCGGTGGCGATGAGGT-3`
Hyd7F	2859-2878	5`-CGCAGGCGATGCA(G/C)GGGTC-3`
GC clamp^c		5`-CGCCCGCCGCGCCCCGCGCCCGTCCCGCCGCCCCCGCCCG-3`

^aThe forward and reverse primers are indicated by the last letters F and R, respectively.
^bPositions in the [NiFe] hydrogenase gene of D.vulgaris [8]
^cThe GC clamp is attached to the 59 end of the Hyd1F primer.

Table 1: Primer sequences and positions.