<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div>Hello!</div><div><br></div>We've recently been having issues with 10nm gold beads (the type used in tomography) from Sigma forming poorly behaving aggregates. It varies batch to batch; in the past the beads from Sigma have been fine, but not on the last two occasions.<div><br></div><div>We typically BSA treat the beads followed by washing. Unfortunately, they have been crashing out in recent preparations (visible in that the solution turns dark purple/grey instead of staying burgundy).<br></div><div><br></div><div>Does anybody have a reliable, recently used source for these types of gold beads? Or any advice on recovering them if they appear to have gone "bad"?<div><br></div><div><div>Many thanks,</div><div><br></div><div>Kelly Lee <div><br><div apple-content-edited="true">
<span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px;"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>________________________________</div><div><br></div><div>Kelly Lee, Ph.D.</div><div>Department of Medicinal Chemistry</div><div>University of Washington</div><div><br></div><div><a href="mailto:kklee@u.washington.edu">kklee@u.washington.edu</a></div><div><a href="http://faculty.washington.edu/kklee">http://faculty.washington.edu/kklee</a></div><div><br></div><div>University of Washington</div><div>Department of Medicinal Chemistry</div><div>PO Box 357610</div><div>Seattle, WA 98195-7610</div><div><br></div><div>206-616-3972 (office Health Sciences Bldg H172J)</div><div>206-616-3496 (lab Health Sciences Bldg H073)</div><div>206-685-3252 (fax)</div></div></span></div></span></span>
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