Commission Directive 2006/63/CE of 14 July 2006 amending Annexes II to VII to Council Directive 98/57/EC on the control of Ralstonia solanacearum (Smith) Yabuuchi et al. (c. 63)

ANNEX

“Appendix 5 Determination of contamination level in IF and FISH tests

1.

Count the mean number of typical fluorescent cells per field of view (c).

2.

Calculate the number of typical fluorescent cells per microscope slide window (C).

C = c × S/s

where	S	=	surface area of window of multispot slide
and	s	=	surface area of objective field

s = πi2/4G2K2	where	i	=	field coefficient (varies from 8 to 24 depending upon ocular type)
		K	=	tube coefficient (1 or 1,25)
		G	=	magnification of objective (100 ×, 40 × etc.).

3.

Calculate the number of typical fluorescent cells per ml of re-suspended pellet (N).

N = C × 1 000/y × F

where	y	=	volume of re-suspended pellet on each window
and	F	=	dilution factor of re-suspended pellet.”