1. Exercise 57: Bacterial Counts on Foods
Lab 20 Goals and Objectives:
Exercise 57: Bacterial Counts on Foods
Count colonies: calculate CFU/gram (meat, spinach) or CFU/ml (milk) *Remember, plates of only!
Exercise 59: The Membrane Filter Method
Check filters for coliforms: (examples of Escherichia and Enterobacter on EMB provided to demonstrate appearance of coliforms)
Count coliforms, report as CFU/ml
Biotechnology Practice Exercise
Each pair get: Two Pipettors, Box of tips, Tube of colored water, Two squares of parafilm: Practice pipetting 5µl water: make a 3 X 3 5µl drop pattern on the parafilm and check that all drops look the same size
EDVOKIT#300: Blue/White Cloning of a DNA Fragment
Work in five groups total (double up with another pair?)
Set up the ligation (tube 1) and ligation control (tube 2) reactions according to directions on pg 13. When done, put in rack to incubate.

2. Figure 69.3: EMB Agar (Endo MF broth is similar)
Selective for Gram-Negative
Differential for coliforms: dark centers or metallic green

3. To “clone a gene”: means to copy the gene from its original natural genomic source and to put it into a plasmid/vector for expression (protein product) or other experimental use.
Figure 66.1

4. EDVO page 5

5. Restriction enzymes cut DNA at certain base sequences leaving “sticky ends” that “want” to ligate with other complementary sticky ends.
EDVO page 6

6. Vector + gene we want to clone + ligase
~incubate~
Two possible products:
-gene ligated into vector 
-vector religated without gene 

7. Experiment Overview
Ligation
Transformation
EDVO page 7

8. Biotechnology Tools
Micropipettor Practice
- touch tip to surface when dispensing
- “blow out” sample and pull away before letting go of plunger
Good consistent pipetting!
Need more practice!

9. Set up ligation
EDVO page 12 &13

10. Exercise 57: Bacterial Counts on Foods
Lab 20 Goals and Objectives:
Exercise 57: Bacterial Counts on Foods
Count colonies: calculate CFU/gram (meat, spinach) or CFU/ml (milk) *Remember, plates of only!
Exercise 59: The Membrane Filter Method
Check filters for coliforms: (examples of Escherichia and Enterobacter on EMB provided to demonstrate appearance of coliforms)
Count coliforms, report as CFU/ml
Biotechnology Practice Exercise
Each pair get: Two Pipettors, Box of tips, Tube of colored water, Two squares of parafilm: Practice pipetting 5µl water: make a 3 X 3 5µl drop pattern on the parafilm and check that all drops look the same size
EDVOKIT#300: Blue/White Cloning of a DNA Fragment
Work in five groups total (double up with another pair?)
Set up the ligation (tube 1) and ligation control (tube 2) reactions according to directions on pg 13. When done, put in rack to incubate.