Media components and some cellular components can reduce the A_260/A230 ratio. Following the protocol will ensure these contaminants are removed. Additionally, some particulates may elute with the DNA, affecting the ratio. If this is the case, perform an additional 15-second spin of the eluted DNA to settle the particulates before evaluation by spectrometry (Nanodrop^®) should help. Withdrawing the DNA sample from the top of the sample can help avoid transferring any particulates.