Insights Into Cake Development

Having demonstrated that the filtration behavior for washed cells was not unduly affected by labeling, some insights into cake structure and development can be made. 

Filtration with 0.37 g washed yeast suspensions at TMP 0.10 bar and a cross-flow velocity (CFV) of 0.20 m s resulted in a much thicker cake and the evolution of cake thickness had to be estimated from drying and weighing of the cake as the MPM was found to be limited to about 40 pm. Incidentally after 60 min the estimated cake thicknesses from drying and weighing was 165 pm with a corresponding specific cake resistance of 5.48 x 10 mkg, which is in excellent agreement with literature values [34, 35]. 

Although penetration of 200 pm was achieved through mouse skin [36], densely packed cakes of cells are less transparent that skin and most biological specimens, hence the observed limitation of around 40 pm. Notwithstanding this limitation, structural details of the top layers of the final cake and details as it develops can be obtained by MPM. It was found [32] that macrovoids (in the order of a cell) exist 

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