Why is my absorbance value of 260/230 close to 0 after purifying the PCR sample?

When I measure the concentration and quality of the purified PCR product, the value of 260/280 is within the range of 1.8 - 2.2, while the value of 260/230 is always close to 0. Why is this...

11 June 2022 9,866 4 View