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BISC209/F13: Lab2: Difference between revisions
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→Abundance Test 2: Enumeration of Community Soil Microorganisms by Direct Count of Microbial DNA Stained & Viewed by Fluorescence Microscopy
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=='''Abundance Test 2: Enumeration of Community Soil Microorganisms by Direct Count of Microbial DNA Stained & Viewed by Fluorescence Microscopy'''== | =='''Abundance Test 2: Enumeration of Community Soil Microorganisms by Direct Count of Microbial DNA Stained & Viewed by Fluorescence Microscopy'''== | ||
You can directly count a random sample of microbes from the soil extract that you prepared last week and then extrapolate the number per gram of soil. To make the microbes easier to count, you stained the nucleic acids of your soil community microbes (not just the bacteria) with a fluorescent 4'-6-Diamidino-2-phenylindole (DAPI) DNA stain. All the microbes in a 1ml aliquot of the 1% soil extract that you prepared last week were transferred in a Poisson distribution to a small piece of filter paper. Your instructor photographed the discreet bright "spots" of fluorescent DNA in several different areas of the filter paper distribution using fluorescence microscropy. You will each count the discreet "spots" (individual microorganisms = one fluorescent genome/cell) | You can directly count a random sample of microbes from the soil extract that you prepared last week and then extrapolate the number per gram of soil. To make the microbes easier to count, you stained the nucleic acids of your soil community microbes (not just the bacteria) with a fluorescent 4'-6-Diamidino-2-phenylindole (DAPI) DNA stain. All the microbes in a 1ml aliquot of the 1% soil extract that you prepared last week were transferred in a Poisson distribution to a small piece of filter paper. Your instructor photographed the discreet bright "spots" of fluorescent DNA in several different areas of the filter paper distribution using fluorescence microscropy. You will each count the discreet "spots" (individual microorganisms = one fluorescent genome/cell) and perform the calculations described below to assess the total microbial concentration in this ''culture-independent'' enumeration of your soil community's microorganisms. <BR><BR> | ||
'''COUNTING & CALCULATIONS:'''<BR> | '''COUNTING & CALCULATIONS:'''<BR> | ||
