3,811
edits
BISC209/F13: Lab7: Difference between revisions
From OpenWetWare
Jump to navigationJump to search
→McFarland Turbidity Standards
| Line 54: | Line 54: | ||
2) You will use the fresh broth culture of each of your isolates that you prepared prior to lab for both the antibiotic and interactions protocols. We want to apply relatively the same number of organisms in each procedure so we will use McFarland Standard to "correct" turbidity. <BR> | 2) You will use the fresh broth culture of each of your isolates that you prepared prior to lab for both the antibiotic and interactions protocols. We want to apply relatively the same number of organisms in each procedure so we will use McFarland Standard to "correct" turbidity. <BR> | ||
3. If your fresh broth is more turbid than the McFarland Standard, pipet one ml of the broth culture into a sterile glass tube and adjust the concentration of the cells by matching by eye the "cloudiness" (turbidity) of the cells in the glass tube to a standard provided by your instructor. <BR> | 3. If your fresh broth is more turbid than the McFarland Standard, pipet one ml of the broth culture into a new empty sterile glass tube and adjust the concentration of the cells by adding NB or sterile water and matching by eye the "cloudiness" (turbidity) of the cells in the glass tube to a standard provided by your instructor. <BR> | ||
4) If your fresh broth is less turbid than the McFarland Standard, add bacteria from a freshly grown colony of the isolate grown on solid medium to concentrate the cells. <BR> | 4) If your fresh broth is less turbid than the McFarland Standard, add bacteria from a freshly grown colony of the isolate grown on solid medium to concentrate the cells. <BR> | ||
