Transformation Instruction on XL1 cells

Protocol of transformation:

Prepare the HeatBlock and shaker before getting XL1 cells

1. Put water into the blocks

2. Turn on the heatblock and set the temperature at 65C

3. Put a thermometer in the heatblock to track the temperature

4. Turn on the shaker, 250 rpm, 37C

Start the Trasnformation

1. Take out XL1 cells from -80 freezer and thaw on ice
*The ones we use in the lab have 50ul of cells/tube

*Make sure to take out some spares in case there's not enough cells

2. Take out SOC and the same time and thaw at room temperature

*If you need to use an old one, make sure it looks clear

3. Prepare some 2ml tubes: one tube for each transformation and label the tube with the name of the plasmid

4. Set the pippetors ready:

One P200 at 115ul for XL1 cells

One P2 at 2ul for plasmids

One P1000 at 500ul for SOC

5. Open some XL1 cells and leave the tubes on ice

6. Mix tubes of XL1 cells by pipetting

*Do not centrifuge XL1 cells since they are fragile

*If there’re big drops of cells on the edge, use the pippet tips to get it down to the bottom

*If there’re small drops of cells on the edge, just leave it

7. From the mixed tube, take out 115ul of XL1 cells and add to the marked 2ml tubes

Leave the tubes on ice after added XL1 cells

8. Add 2ul of plasmids to 115ul of XL1 cells

9. Leave the 2ml tubes in fridge for 30 minutes

10. Take the tubes out

11. Heat shock at 42C for 45 seconds in HeatBlock

12. Take the tubes out

13. Leave the tubes in fridge for 2 minutes

14. Take the tubes out

15. In the hood, add 500ul SOC into the cells

*Drop the SOC onto the cells nice and slow

*No need to mix afterwards

16. Leave the tubes in the shaker for 4 hours

How To Make Saturated Salt Solution

In our lab, we use saturated salt solution to test the effects of salt concentration on behavior of freshwater organisms.

Make saturated salt solution:

NaCl	360g
DI water	1L

***Stir until no more salt is dissolving. Add more salt if no more salt left, add water is too much salt left. The final solution should have a little salt at the bottom indicating that the salt solution is saturated.

Notes:

1.      A saturated solution is a solution that contains the maximum amount of solute that is capable of being dissolved.

2.      At 20°C, the maximum amount of NaCl that will dissolve in 100g of water is 36.0g. If any more NaCl is added past that point, it will not dissolve because the solution is saturated.

One beaker of 1L saturated salt solution (with a little undissolved salt at the bottom):