It doesn't sound like it. I'm not at all familiar with Quest Diagnostics and their services. When I did my stool culture, I had to collect two samples at home and put them into a special container the lab at my medical center provided. They had to be kept cold, too, to keep all of the bacteria that are normally present in the stool from overgrowing too much. I'm pretty sure that when they are looking for a specific organism, the stool is plated on to a special medium that will encourage the growth of that specific organism, and/or inhibit the growth of organisms they are not looking for.
I'm a plant researcher, and this is how many plant diseases (fungal and bacteria) are identified, so I assume it's quite similar!
Symptoms began in November 2008, ~4 weeks after giving birth to my son.
Eased for ~3 weeks in December, possibly b/c of probiotic use?
Returned in January 2009 (with a vengeance), diagnosed with pancolitis on January 30.
Currently taking Asacol (400mg 4 pills 3x daily), Rowasa nightly, 40mg of Prednisone (quick taper), Culturelle probiotic, and Zoloft (25 mg).