In our lab prep space, we have the following solutions and powders: Sodium citra
ID: 207075 • Letter: I
Question
In our lab prep space, we have the following solutions and powders:
Sodium citrate (FW = 43.7 g/mol)
SDS powder (FW = 288.38 g/mol)
0.5 M EDTA
IPTG powder (FW = 238.3 g/mol)
20 mg/mL X-gal solution
1000X ONPG
Premade LB
Premade LB agar
0.5 mM Colchicine
50X gel running buffer
Agarose powder
95% ethanol
100 mg/mL Ampicillin
10X BamHI restriction enzyme digestion buffer
milliQ water
dimethylformamide (DMF)
Questions:
2) (hemoglobin) How would you make 100 mL 1X running buffer for your gel?
3) (B-gal) How would you make 48 ml of a 1X ONPG solution?
5) (restriction enzyme digestion). You are planning to do a 45 ml restriction digestion with BamHI. How much 10 X restriction enzyme buffer do you need to include?
13) . (B-gal) How would you make 500 mL LB + 40 mg/mL X-gal? (the LB is made, so you just need to figure out how much X-Gal to add)
Explanation / Answer
For making running buffer stock is 50 X and you have to make 1X buffer finally 100 ml
50 X* Y (ml is required)= 1X* 100
Y= 100/50= 2 ml
In this preparation and 2ml of 50 X buffer is required and final volume will be set 100 ml.
48 ml of 1X ONPG
Stock solution is 1000 X
1000 X * Y ( ml is require)= 48 *1 X
Y= 48/1000= 0.048 ml or= 48 microliter is required.
In this question for enzyme reaction iw carried out at microliter level not at ml level( as given in question) but factor of dilution level is same
10 X stock
Final volume for reaction
10 X * y (ml si required) = 1X * 45
Y= 45/10= 4.5 ml or ul as per requirement
Add 4.5 ml or ul and make final volume 45 ml or ul
In this question the stock concentration 20 mg/ml and in LB it required 40 mg/ml to make. Here we can make higher to lower concentration but low to higher can not make.
Generally in LB X-gal concentrations are in ug/ml ( microgram/ml) is required.
20 mg/ml can also be write 20000ug/ml
20000ug/ml * X ( ml is required)= 500 * 40ug/ml
X= 500 * 40/20000=20/20= 1ml
1ml is required.
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