Question

You have been provided a spectrophotometer and three solutions. One of the solutions is that of a DNA while the other two are solutions are of a protein and of glucose. How you can identify the DNA solution? Explain. What test you can perform to make sure that the identified solution is that of DNA and not of a nucleotide?

Answer 1

Answers:

In questions we have spectrophotometer so we will proceed witho density measurements. As we all aware thatN Nucleicacids have absorbance maxima at 260 nm. Historically, the ratio of this absorbance maximum to the absorbance at 280 nm has been used as a measure of purity in both DNA and RNA extractions. A 260/280 ratioof ~1.8 is generally accepted as “pure” for DNA; a ratio of ~2.0 is generally accepted as “pure” for RNA.

In case of  purified proteins, the 260/280 ratio can be a useful tool to determine the purity of an isolated protein. An ideal 260/280 ratio for common proteins is 0.6. Higher ratios may indicate the contamination of isolated proteins with DNA.