How to determine sample size for microbiological analysis?

Am looking for data - number of samples that need to be drawn for Microbiological examination for the day in a hotel industry. Is there any such formula to calculate no. of samples. any information is much appreciated.

Thanks for all the help

Dear milagr,

A few of the possible related factors –

Sampling what (risk) type of product ?
Sampling for what bacterium ?
Sampling for any particular regulatory standard ?

ie. more info needed please.

One classic on-line source is USA / BAM. Another is ICMSF. There are many others for different localities.

Some practical UK examples for RTE products –

www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1194947422163

Rgds / Charles.C