Capsular bags and FHL124 cells were placed in homogenizing medium
(composition in millimolar: phosphate 6, KCl 100, NaCl 225, EGTA 1,
EDTA 1, mercaptoethanol 10, N-ethylmaliamide 10,
phenylmethylsulfonyl fluoride [PMSF] 0.05, and E-64 0.005 and 1%
vol/vol Tween 20, [pH 7.4]), before storage in a −70°C freezer.
One hundred microliters of the homogenates and medium samples were
analyzed for human HGF using commercially available ELISA kits (R&D,
Abingdon, UK). The optical density of each well was determined using
the multiwell plate reader (Victor; EG&G Wallac, Cambridge, UK) at a
wavelength of 450 nm. The readings from the standard series were
plotted with logarithmic axes, and the data from the samples were then
applied to the graph giving the estimated level of growth factor in
picograms per milliliter. The limit of sensitivity of the system is 40
pg/ml, and any sample below this limit was treated as being zero. In
the case of homogenate samples, values were used to determine total HGF
per bag.