Hi, I cannot use NiCl2 and I am having trouble immobilizing DNA onto mica using MgCl2 buffer (10 mM HEPES, 10 mM MgCl2, PH 7.5). The stock DNA is diluted 40x in this deposition buffer. After depositing the DNA onto mica for 1 minute, it is rinsed with double distilled water and dried with Argon. Most of the time I observe DNA that is clumped up forming