TABLE 6.

Serum neutralizing activity against in vitro cytotoxicity of CDTA for HT-29 cells^a

Immunogen	μg of Ab/ml (ELISA)	Reciprocal neutralization titer
		GM	Range
Pn14-rARU	194	104	64–256
Pn14-rARUsucc	371	111	64–128
SF-rARU	613	194	64–256
SF-rARUsucc	518	111	64–256
K1-rARUsucc	390	181	64–256
Goat antitoxin (0.5 mg/ml)b		128
PBS		0

^aNeutralizing titers were the highest serum dilution that completely inhibited the cytotoxicity of CDTA (20 ng/well) on HT-29 cells (Materials and Methods). The titers represent the geometric means (GM) ± standard deviations from general-purpose Swiss Albino mice (n = 10) obtained 7 days after the third injection. Anti-CDTA was also measured by ELISA, and the individual values are expressed as micrograms of Ab per milliliter of serum. 

^bAffinity-purified goat Ab.