In order to inoculate 1 liter of medium with a final cell co

In order to inoculate 1 liter of medium with a final cell concentration of 100 cells per ml, you need to inoculate with_____ mu l of a starter culture that has a cell density of 10 cells/ml. 1 mu l 1,000 mu l 100 mu l 10 mu l 200 mu l of 0.5 M NaCI diluted with 800 mu l water results in a final concentration of 100 mmol/ster 100 mM 100 mmol/ml 0.1 M You need to dilute a 1 M solution of Tris buffer to 10 mM which is a 1:_____dilution. Assume that the same volume was spotted on each spot of the agar plate. Therefore, there are approximately _____ x as many cells in the spots of the first (I/I) column than in the last column (1/1000). 1/1000 1,000 10 100

Solution

Q3. (A) 0.1 uL

Stock= 10 ^7 cells/mL

Required = 100 cell/mL

Required volume = 1L =1000mL

C1V1= C2V2

(stock)   (required)

V1=C2V2/C1

V1 = ( 100 x 1000 mL)/10 ^7

= 10 ^-2 mL

=0.1uL

Q4. (A) 100

1M tris to 10mM

1M=1000mM

Dilution factor = Final Concentration/initial concentration

=10mM/1000mM

=1/100

Q5. (D) 0.1 M

200 uL 0.5 M NacL + 800 uL H2O

Total volume = 1000uL

Fold Dilution = 1000/200 = 5

Final concentration of NaCl = 0.5/5 = 0.1M