sample analysis of "whole" vegetable - (Dec/16/2013 )

Hello,

I collected samples of raw vegetables for analysis (lettuce and parsley) from farms.

How and what is the best way  to prepare the weighing of the whole piece of vegetable ? do I take the 10 g sample from each side of lettuce or i  cut the lettuce leaves using sterile tools and  get a mix of 10 grams of it ?

I still google for a reference but :((

Thanks in advance for the advice :)

Good day to all.

Sampling for what? DNA? RNA? protein? viruses? bacteria? fungi?...

bacterial testing. I want to test the samples for coliforms, E.coli, listerian monocytogenes and salmonella. when i prepare the 10 g and 25 g sample from a whole lettuce , do i take the 10g for instance from the different side of a lettuce?

sorry for not being clear on my earlier post

Though not being a microbiologist, my idea is that you have to know if the distribution of bacteria is quite homogeneous over the plant or not. If not you have to consider different parts, e.g. different heights of the plants (e.g. leaves from ground, middle part, upper part) or with lettuce outer and inner plant parts or different organs (e.g. root/stem/leaves/flowers). It depends surely how bacteria are entering the plant or if they only occur on the surface, or if only edible plant parts are considered.

Anyway there should be established protocols available.

edit:

perhaps stuff like this:

Collins, C.H. (2004).  Collins and Lyne’s microbiological methods. 8th ed., New York, NY: Arnold

FDA Bacteriological analytical manual. 8th ed. AOAC International, Gaithersburg, Md.