A sandwich ELISA was developed and its speci®city was investigated
using L-forms and cell-walled forms of B. subtilis, different Bacillus species and a range of
bacteria isolated from glasshouse-grown strawberry plants. The detection limits of the
ELISA were approximately 103 viable cells mlÿ1 for L-forms compared with 107 viable cells
mlÿ1 for cell-walled forms. Results showed that L-forms survived and moved within
strawberry tissues injected with L-form bacteria