Hi everybody.
I am inquiring your help considering the pt scheme for salmonella testing in swabs. In our lab, for this type of analysis we are using standard SRPS EN ISO 6579:2008. And while we are awaiting our test sample, we got a preliminary instruction from LGC about the preparation of the sample, and it states that after swabbing the inoculated the plate and placing the swab into primer diluent (buffered peptone water), we should take 5ml of it, and add it to the enrichment broth ( RVS). Well, the instruction did not say what should be the volume of the RVS. By are standard, we add 0,1 ml of the sample to 10 ml of RVS. And following that logic, then we should add 5 ml to 500 ml. Is not that a little bit too much possibly? Maybe then the sample will be too diluted? This is our first time that we are doing pt schemes for swabs, and any help will be welcomed :)
Thanks in advance