Lab 10 - Bacterial Growth II

November 7 9 2012 spectrophotometric analysis example

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Unformatted text preview: 7- 9, 2012 23 Agar Plate Analysis •  You only need to be able to count one plate to calculate the iniTal concentraTon of your E. coli bacterial culture. •  If you cannot count the colonies on your plate normally for some reason (eg, a water smear on part of your plate), you can use a representaTve region of your plate and mulTply your count to calculate an approximaTon of your total plate count. •  It can help to use a marker and make a dot over each colony as you count it, so that you do not count it twice. Lab 10. November 7- 9, 2012 Combining your Serial DiluTons •  You have concentraTons from agar pour plates. •  You have absorbance data from spectrophotometry. 24 Lab 10. November 7- 9, 2012 25 Serial diluTon for spectrophotometry Lab 10. November 7- 9, 2012 26 Combining your Serial DiluTons •  You have absorbance data at for your bacterial culture at various diluTons (1/2, 1/4, 1/6, 1/8, 1/12, 1/16, 1/24). •  MulTply these fracTons by the starTng concentraTon to determine the approximate concentraTon (CFU/mL) at those concentraTons. 27 Lab 10. November 7- 9, 2012 Spectrophotometric Analysis Tube Number Dilu?on Absorbance (OD600 nm) CFU/mL Undiluted — — Calculated from agar plates 1 1/ 2 USE 2 1/ 4 YOUR 5 1/ 6 ABSORBANCE 3 1/ 8 DATA 6 1/ 12 FROM 4 1/ 16 LAST 7 1/ 24 WEEK 28 Lab 10. November 7- 9, 2012 Spectrophotometric Analysis EXAMPLE Tube Number Dilu?on Absorbance (OD600 nm) CFU/mL Undiluted — — Calculated from agar plates 1 1/ 2 0.210 ? 2 1/ 4 0.117 ? 5 1/ 6 0.080 ? 3 1/ 8 0.061 ? 6 1/ 12 0.026 ? 4 1/ 16 0.020 ?...
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This note was uploaded on 01/06/2013 for the course BIOL 1902 taught by Professor Murry during the Spring '13 term at University of Winnipeg.

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