Th e purity of DNA extractions is measured by calculating the ratio between the

Question

Th e purity of DNA extractions is measured by calculating the ratio between the absorbance peak of DNA (A260) and the absorbance peaks of common contaminants like protein which absorb strongly at 230 nm (A230). For DNA, an Az6o/A280 ratio of ~1.8 and/or an A260/A230 ratio of 1.8-2.2 is generally accepted as "pure". What are the Az8o and A230 OD values for your DNA extraction? Based on these values, how pure is your DNA extraction (show your work)? If it isn't pure, what do the ratios indicate are contaminating your extraction? (4 points) s which have a peak absorbance at 280 nm (A280), or chaotropic salts

Explanation / Answer

The OD (absorbance) value of my extrations are as follows:

A260 = 0.401

A280 = 0.223

A230 = 0.218

Hence the value of A260/ A280 = 1.798 and the value of A260/ A230 = 1.83

According to the given range of acceptance my DNA extraction is pure as the ratio indicates the value within the range. Lower value of these ratio indicates less purity while higher value indicates higher purity.

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A T

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