Plating efficiency

A plating efficiency is a measure of the number of colonies originating from single cells. It is a very sensitive test and is often used for determining the nutritional requirements of cells, testing serum lots, measuring the effects of growth factors, and toxicity testing.

Plating Efficiency (abbreviated as PE) is the number of cells that grow into colonies per 100 cells inoculated. That is, it is the proportion of cells that attach and grow to the number of cells originally plated, expressed as a percentage. PE can be determined by the following formulae:

PE(%)= (# Cells Day 1 /# Cells Plated Day 0) x 100

or

PE(%)=(Colonies Counted / Cells Inoculated) x 100 

The first method is more accurate.

Cell growth in culture generally undergoes a decline after plating, and graphically, PE is the global minima (lowest point) of the growth curve at day one, after which growth rises again. The decrease in viable cells after plating is due to "anchorage-dependence"--cells must attach to the bottom of the culture dish.

Plating Efficiency is one of the parameters typically used to define growth properties of cells in culture. Other common parameters are doubling time (DT) (which is an average of generation time (GT)), and saturation density (SD).

Reference

Mather, J.P., and P.E. Roberts, 1998. Introduction to Cell and Tissue Culture: Theory and Technique. Plenum Press. New York and London.