As you complete these problems COPY the results into your lab notebook for use d
ID: 1008009 • Letter: A
Question
As you complete these problems COPY the results into your lab notebook for use during your lab. You need to create 6 serial Dilutions of BUN standards with a total volume of 1 mL each. You are provided with a 60 mg/dL stock BUN solution. The first concentration required is provided in the table below. Create a series of dilutions by cutting the concentration in half each time. Complete the following table based on the use of the information above to make the following PPM concentrations of BUN. (1 mL of total volume is used) (Give answers to 3 sigfigs):Explanation / Answer
Dilution 1
The stock conc. is 60 mg/dL ---- Let's consider it as C1
The required concentration is 53 mg/dL ------- Let's assume it as C2
The final volume we need is mL
Using dilution formula we have
C1V1 - C2V2
60 mg/dL * V1 = 53 mg/dL * 1 mL
V1 = 0.883 mL
The conversion factor for mL to uL conversion is
1 mL = 1000 uL
Volume of BUN needed : 0.883 mL * 1000 uL/1 mL = 883 uL
Volume of BUN needed = 883 uL
Volume of saline buffer needed = 1000 - 833 = 167 uL
The concentration given to us is 53 mg/dL
Let's convert it to ppm
1 ppm = 1 mg/L
Let's convert above unit from mg/dL to mg/L
53 mg/dL * 10 dL/ 1 L = 530 mg/L = 530 ppm
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Dilution 2
We want to cut the concentration in half.
So C2 = 53 /2 = 26.5 mg/dL
V2 = mL
Since we are preparing serial dilution, our initial solution would be 53 mg/dL
C1 = 53 mg/dL
C1V1 = C2V2
53mg/dL * V1 = 26.5 mg/dL * mL
V1 = 0.5 mL = 0.5 mL * 1000 uL/ 1 mL = 500 uL
BUN (mg/dL) = 26.5 mg/dL
Volume of BUN needed = 500 uL
Volume of saline buffer needed = 1000 - 500 = 500 uL
26.5 mg/dL * 10 dL/ 1 L = 265 mg/L = 265 ppm
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Dilution 3
C1 = 26.5 mg/dL
V1 = ?
C2 = 26.5/2 = 13.25 mg/dL
V2 = 1 mL
26.5 mg/ dL * V1 = 13.25 mg/dL * 1 mL
V1 = 0.5 mL = 0.5 mL * 1000 uL/1 mL = 500 uL
BUN (mg/dL) = 13.25 ~ 13.3 mg/dL
Volume of BUN needed = 500 uL
Volume of saline buffer needed = 1000 - 500 = 500 uL
13.25 mg/dL * 10 dL/ L = 132.5 mg/L = 133 ppm
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Dilution 4
C1 = 13.25 mg/dL
V1 = ?
C2 = 13.25/2 = 6.625 mg/dL
V2 = mL
13.25 mg/dL * V1 = 6.625 mg/dL * mL
V1 = 0.5 mL = 0.5 mL * 1000 uL/1 mL = 500 uL
BUN (mg/dL ) = 6.625 mg/dL
Volume of BUN needed = 500 uL
Volume of saline buffer needed = 1000 - 500 = 500 uL
6.625 mg/dL * 10 dL/ L = 66.25 mg/L = 66.3 ppm
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Dilution 5
C1 = 6.625 mg/dL
V1 = ?
C2 = 6.625/2 = 3.3125 mg/dL
V2 = mL
6.625 mg/dL * V1 = 3.3125 mg/dL * 1 mL
V1 = 0.5 mL = 0.5 mL * 1000 uL/ 1 mL = 500 uL
BUN needed (mg/dL) = 3.3125 mg/dL ~ 3.31 mg/dL
Volume of BUN needed = 500 uL
Volume of saline buffer needed = 1000 - 500 = 500 uL
3.31 mg/dL * 10 dL/ L = 33. mg/L = 33.1 ppm
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Dilution 6
C1 = 3.3125 mg/dL
V1 = ?
C2 = 1.656 mg/dL
V2 = 1 mL
3.3125 mg/dL * V1 = 1.656 mg/dL * 1 mL
V1 = 0.5 mL = 0.5 mL * 1000 uL/1 mL = 500 uL
BUN needed ( mg/dL) = 1.656 mg/dL ~ 1.66 mg/dL
Volume of BUN needed = 500 uL
Volume of saline buffer needed = 1000 - 500 = 500 uL
1.66 mg/dL * 10 dL/ 1 L = 16.6 mg/L = 16.6 ppm
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