UW-Stout/Nonionic Detergent SP22

Pilot experiment: Testing NLS effect on WT yeast cells growth

Introduction: In this experiment, we will be testing the effect of N-Lauroylsarcosine on the speed of growth of wild type yeast cells. Our objective is to find the concentration of NLS needed to affect the yeast cell growth without killing them all. Materials: • (NLS) N-Lauroylsarcosine sodium salt >=94% • Corning COSTAR 96-well clear flat-bottom assay plate • Wild-type yeast in 2x synthetic complete media at an OD600 of 0.1-0.2 Equipment: • Molecular Devices SpectraMax Plus 384 Microplate Reader Procedure: 1. Make a 0.1% solution of NLS by putting 1µl of a 10% solution of NLS in 99 mL of water. This is going to give you a 100 mL solution with a 0.1 concentration of NLS. 2. Use the 0.1% solution of NLS to make 7 different concentrations of N-Lauroylsarcosine (0%, 0.001%, 0.002%, 0.005%, 0.01%, 0.02%, 0.05%). To increase solubility, temperature can be increased to 25-30°C. 3. Set up 8 wells according to following table.

	Well A (0%)	Well B (0.001%)	Well C (0.002%)	Well D (0.005%)	Well E (0.01%)	Well F (0.02%)	Well G (0.05%)	Well H (0.1%)
Yeast culture	50µl	50µl	50µl	50µl	50µl	50µl	50µl	50µl
0.1% solution of NLS	X	0.5µl	1.0µl	2.5µl	5.0µl	10µl	25µl	50µl
Deionized water	50µl	49.5µl	49µl	47.5µl	45µl	40µl	25µl	X

4. Set up the plate reader as follows:

Temperature: 30°C Mode: Kinetic Wavelength: 600 nm Interval: 5 minutes Total run time: 24 hours Shake before read: 30 seconds

5. Transfer the assay plate to the reader and read for 24 hours. Notes • Results:

-Here is the graph obtained after following the procedure above and putting it in the plate reader for 24 hours:

-Under is a graph with a Y axis scale set to logarithmic so we can find the doubling-time of the WT yeast cell in well B,D,E,F when mixed with a 0.001% solution of NLS:

Doubling time of Well B, D, E, F

-Td (Well B)= 547 minutes -Td (Well D) = 1442 minutes -Td (Well E) = 1086 minutes -Td (Well F) = 496 minutes -Td (average) = 893 minutes

Doubling Time for Well A (0% NLS) and Well C (0.002% NLS):

-Td (Well A) = 302 minutes -Td (Well C) = 10 570 minutes

• Analysis and Conclusions:

-According to the graph above and the doubling time found, we noticed that in well A (with only water), the growth of the WT yeast cell was significant with a doubling time of 302 minutes. In Well C (0,002% NLS), practically no growth occurred with having a doubling time of 10 570 minutes. Following this information, we concluded that 0,002% NLS was too concentrated for any growth to occur.

-Furthermore, after seeing that well B’s growth rate graph and its doubling time (893 minutes) were situated in between A’s and C’s, we concluded that 0,001% was the concentration we were going to use.

-Important to note: the concentration used need to be divided by 2 because out of the 100µl solution, 50µl is yeast cell so it dilutes the previous dilution. With that being said, we are technically using 0,0005% NLS.