Table 2. Contribution of surface amplification.

	A		B		C		D	E
Cycle number	1, 2	3–30	1, 2	3–30	1, 2	3–30	1–30	1–30
DNA template I8	+	–	+	–	+	–	+
DNA template E1-2								+
DNA polymerase	+	–	+	+	+	+	+	+
Amplified DNA coverage (fmol/mm2)	0.0011 0.0002		0.0029 0.0002		0.0028 0.0003		0.0190 0.0002	0.0000 0.0001

Glass slides were prepared as described in Figure 4. Glass slides were submitted to two first solid phase PCR cycles (1, 2) with a 1 nM solution of template (I8) and Taq polymerase. Then 28 additional cycles (3–30) were run using the following procedures: A, without DNA template or DNA polymerase in solution; B, without DNA template but with DNA polymerase in solution; C, as B but with fresh PCR mix after each cycle; D, with DNA template (I8) and DNA polymerase in solution; E, as D but using control template (E1-2). The loading density of DNA molecules (fmol/mm²) amplified on the glass surface was determined by hybridisation with specific radioactively-labelled probe.