A new method for cloning Giardia lamblia, with a discussion of the statistical considerations of limiting dilution.

This report describes a method of cloning Giardia lamblia by limiting dilution which is simpler than the previously described semisolid agar technique and which may also be applied as an assay of cell viability. A discussion of the basic statistics of limiting dilution, which is applicable to any cell type, and a method of statistically comparing colony-forming efficiencies from different cell populations are included. The colony-forming efficiency (CFE) of this method, when applied to late log-phase cultures, is 72.1 +/- 10.05%. When only cells adherent to the sides of culture vials are cloned, the CFE is 87.1 +/- 9.85%.