From: Stetler-Stevenson, Maryalice (NIH/NCI) (stetler@mail.nih.gov)
Date: Fri Sep 12 2003 - 16:48:49 EST
One possible explanation of the different experiences of investigators using these reagents is that some prepare cocktails with the antibody or dilute the antibody. We have found that stability is different in cocktails and in a cheap vial (not tightly capping and not brown) compared to what you observe straight out of the appropriate container. Maryalice Stetler-Stevenson Chief, Flow Cytometry Unit Laboratory of Pathology, NCI, NIH Sometimes you're the windshield, sometimes you're the bug. > ---------- > From: Mario Roederer > Sent: Thursday, September 11, 2003 7:21PM > To: Cytometry Mailing List > Subject: Re: Cy7PE > > Perhaps you are storing Cy7PE conjugates where they get exposed to > light? They are definitely light sensitive. > > In any case, we have used Cy7PE reagents from several manufacturers, > and (at least in the last 3 years) they are usually outstanding. We > also make our own quite routinely (and have done so for 10 years), > and find them to be stable for at least 5 years. > > We have between 50 and 100 Cy7PE reagents in our inventory, and have > never observed this problem. Our stocks are kept in a closed > refrigerator (sorry, we have not verified that the light goes out > when we close the door, but we strongly suspect that it does), and > all reagents are stored in dark glass bottles. > > Therefore, I conclude that either your are not storing your reagents > "optimally", or you have had unusually bad luck with your reagents! > I recommend you try some more. > > mr > > At 10:19 AM +0300 9/11/03, Jeffrey Dorfman wrote: > >Just before anyone goes down the road of Cy7PE, I think a warning is in > >order. I have yet to find a Cy7PE conjugate that I liked. In particular, > the > >link between the dyes seems to be unstable, so after a month or two, the > >antibody conjugate will fluoresce in PE more than in the Cy7 range, > making > >it less useful. This was try of samples tested from both manufacturers > that > >I found, and I Have stopped trying. > > > >If anyone can suggest a manufacturer that makes a good, reliable and > stable > >PE-Cy7 dye, please do let me know. > > > >Best regards, > >Jeff > > > > > > > >On 8/30/03 8:02 AM, "Mario Roederer" <roederer@nih.gov> wrote: > > > ><...> > > > >> > >> Finally, you are correct that using bright Cy5PE stains will diminish > >> your sensitivity in the APC channel because of this--so either use > >> staining combinations for which Cy5PE+ cells are expected to be > >> APC-negative (or conversely, uniformly APC-positive), or switch to > >> using Cy5.5PerCP or PerCP as your FL3 channel (or Cy7PE). > >> > >> mr > >> > >
This archive was generated by hypermail 2.1.6 : Thu Jan 01 2004 - 17:43:54 EST
