A new analytical extraction method was developed for a DNA a

A new analytical extraction method was developed for a DNA analysis in finger print samples. A finger print sample was analyzed six times using the new protocol and found to contain average value of 7580.0 mu g/L with a standard deviation of 10 for DNA. A spike recovery was conducted to validate the accuracy of the new method. A spike of the blood with 150.0 mu g/L DNA gave a concentration of 7725 mu g/L. What is the percentage recovery of DNA spike recovery study? Based on the result of percentage recovery, will you consider the method accurate for DNA extraction? Assuming the \"reference value\" of DNA in the samples is there any significant difference between the result of the finger print analysis and the reference values at 99.9% confident interval?

Solution

A) Ans: The formula for percentage recovery of DNA is given by

% recovery = (Spiked sample result - unspiked sample result) * 100

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  Known spike added concenration

from the above given data

Spiked sample result = 7725 micrograms/mL

Unspiked sample result = 7580 micrograms/mL

Known spike added concentration = 150 micrograms/mL

% recovery = (7725-7580) * 100/ 150 = 96.66%

B) Ans:

Based on the percentage recovery the method is accurate for DNA extraction. Beacuse the % extraction is 96.6%.

C) Ans:

If the reference value is 7560 micrograms / mL and perecntage recovery be 99.9% , the value of the spike should have the DNA content for 7709.85 micro grams/mL.

It can be calaulated as 99.9 % = (spiked value - 7560) * 100/ 150

therefeore spiked value = 7709.85 micro grams/mL.