[Histonet] pepsin pre-digestion before immuno staining
We use trypsin and protease fairly often in our lab in conjunction with immuno staining, but we have not used pepsin. An investigator wants us to use pepsin, and we do have some, but would appreciate any recommendations regarding its use - concentration, time, temperature. Thanks Paul M. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] making 10 % EDTA
The MW of EDTA is 294.2. A 1M solution would therefore contain 294.2 g/L, so a .25M solution would contain 73.55 g/L. A 10% solution would contain 100g/L, so your solution is already less concentrated than 10%. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Methanol
I would contact OSHA and tell them the specifics. The possible vapor contribution of 4 ml of methanol, if it is even measurable, is certainly insignificant from a health/safety perspective. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Unencased Ameoba Stain
Either Gridley's method or an ordinary PAS will work very well, due to the high concentration of glycogen in the amoebic cytoplasm. -Original Message- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of Joseph Brooks Sent: Wednesday, February 27, 2013 11:13 AM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] Unencased Ameoba Stain Hello All, One of our Neuropath docs is inquiring about a special stain for unencased ameobas in cornea biopsies. I did a search and Gridley's Method was the best option that appreaded. Is there someone that could either verify this stain will work on this organism or let me know what you stain you are using? Thanks in advance. Matt Brooks ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Storage of formalin fixed tissue
Long term storage in formalin is not usually recommended. After tissues are completely fixed in formalin, 70% ethanol is better for long term storage. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] eosin in the processor
Eosin won't interfere with binding of antibodies, but eosin is fluorescent. You might want to consider that. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] Gomori Trichrome and nemaline bodies?
Hello All, I work in a core facility providing laboratory services to researchers. I had a request to cut some frozen sections on muscle tissue, and stain them with Gomori Trichrome, a technique we use routinely. I did the stain, checked them microscopically andconfirmed that the collagen fibers were nicely stained. But the researcher came back and said that the slides did not show what she was looking for, which was nemaline bodies, rod-shaped structures indicative of a disease called nemaline myopathy. I had never heard of this but went online and found several articles on the disease, a couple of which showed images of nemaline bodies stained with a modified Gomori Trichrome procedure. But no indications of what the modifications were. Is anyone familiar with the staining of these bodies, either using a modified Gomori trichrome, or some other method? Thanks. Paul Monfils ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Help
I realize that such + slides come with the instruction to completely dry slides at room temperature before placing in the drying oven. I have used these slides for many years, and have found this procedure to be not only unnecessary, but sometimes problematic. I believe sections are more likely to detach if dried at room temperature prior to oven drying. If the section is not lying perfectly flat against the glass - and some types of tissue never do initially - room temperature drying doesn't allow wrinkled areas or other problem areas to effectively spread flat. Points that are in contact with the glass bond electrostatically, but points that are separated from the glass, even by a few microns, do not. Then, when placed into the oven, such raised areas cannot spread flat because closely adjacent areas are already bonded to the slide, and cannot move. After picking up sections from the waterbath, I allow them to stand vertically and drain for no more than 5 minutes, then place them into the drying oven at 70 degrees C. for an hour. I very seldom have any detachment problems with this protocol. Paul M. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] HE
I have also used Surgipath hematoxylin (Gill III) for years, and am having no problems at this time. My last shipment was about 3 months ago. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Oil Red O
Oil Red O slides will never fade. The technique isn't like typical histochemical procedures where dye molecules bind chemically to tissue components. In Oil Red O staining there isn't any chemical binding that can be reversed. What you end up with is a solution of the dye in the fat droplets. Once coverslipped with an aqueous mounting medium, the dye cannot escape from the fat droplets because it is insoluble in water. Therefore the dye in the fat droplets is just as stable as the dye solution in the bottle, and the slides will remain good as long as the coverslipping medium doesn't dry out - which in this case is the reason for refrigeration, to slow the drying of the mounting medium. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] Shandon Tissue Specimen Bags
Shandon Tissue Specimen Bags (nylon biopsy bags) - are they available anywhere? Information on other brands also welcome, but I have used the Shandon bags for many years and am very satisfied with them. Thanks. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] low profile vs. hi profile blades
In my opinion it doesn't make a lot of difference which type you use, since all you actually use is the 2mm or so that extends beyond the edge of the knife holder. What is crucial is that you use the type of blade your knife holder is designed for. If you try to use high profile blades in a low profile knife holder, or vice versa, you will have major problems. Also, high profile blades are available in a heavier, less flexible form for cutting denser tissues. I don't think the low profile blades offer that option, though I am not certain since I use only the high profile format. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] control for Hemoglobin?
Just about any tissue has some small blood vessels with red cells in them. Seems like that should suffice as a control for hemoglobin. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] Cold Plates - Source?
Hello All, Does anyone know where Tissue-Tek cold plates can be purchased? They are plastic, black on the bottom, white on top, gel filled, for chilling blocks. I got them from Cardinal Healthcare a couple of years ago, but I don't see it in their catalog now. Or, if no longer available, a comparable other product? I know I can use a pan of ice, but I prefer something like this if available. Thanks. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] HistoFix and frozen sections
Does anyone here use the fixative called Histofix? If so, does anyone do frozen sections of tissues fixed in it? Or, has anyone attempted it and found it impossible? Thanks for any input. Paul M. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] Thick Paraffin Sections of Rat Brain?
Does anyone cut 40 micron paraffin sections of rat brain? Do you have any problem with fine parallel cracks in the sections (parallel to the knife edge)? Any suggestions for avoiding this? Thanks. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Dry ice alternatives?
Place a container of ordinary ice in the -80 for a couple of hours - or use one of the commercially available cold packs like you use for a picnic lunch, cooled in the -80. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Anatomicalalal
Actually, it's period'-ic for the table - it is arranged in periods. But it is per-io'dic for the chemical, which has nothing to do with periods, but everything to do with iodine! :-) ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Submission of tonsils to pathology
Years ago, when I was in clinical histology, this was an issue being debated by our staff. We had processed thousands of tonsils, and never had a significant diagnosis. They were leaning in the direction of going gross only, when guess what - a lymphoma in a routine tonsil from a 14 year old. So we continued microscopic evaluation on all tonsils. I have now been out of clinical, working in research, for quite a few years, so the policy may have changed since then. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] DMSO in Tissue processor
I never heard of any such recommendations. DMSO doesn't react with plastics or metals, and those are the only surfaces the embedding medium comes into contact with, so I wouldn't expect any problems. In any case, from a personal perspective, I used Paraplast Plus, which contains DMSO, in my processors for many years, and never had a problem. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] band saws
You don't need a large powerful band saw to cut bone. Bone is quite soft compared to the kinds of substances, particularly metals, which those larger band saws can handle. I bought one for my lab over 12 years ago, the smallest, cheapest Craftsman model Sears carried, and it's still going strong. I use it for bone work and also for trimming methyl methacrylate blocks. The most important thing is the type of blade you use. Blades designed for general cutting of wood are too coarse (the teeth are too large) for bone work. A plywood cutting blade might be ok, but I find that blades designed for cutting metal are best. The teeth are much finer (I use blades with 14 teeth per inch), and they have the added advantage of staying sharp a lot longer than a wood cutting blade. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] saliva for glycogen hydrolysis
Those who use human saliva rather than diastase - for how long do you apply the saliva? At what temperature? Do you cover the saliva and section with a coverslip during treatment? I used to do this many years ago, but have been using diastase for so long now that I don't remember the particulars of the saliva method, and few books seem to provide that information. Thanks. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] Vibratome sectioning of lung
Does anyone have experience sectioning agarose-embedded lung sections on the Vibratome? I have cut sections of various tissues on the Vibratome, but am having a very difficult time with mouse lung. The agarose does not seem to adhere to the tissue, and the blade simply pulls the tissue out of the agarose block. Any suggestions will be most appreciated. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Frozen section ...HELP
Hopefully you removed the antifreeze (alcohol) before freezing? :-) I have run into this a few times. I work in a core facility where people send me samples from all over. Recently someone sent me some samples fixed in Histofix, which is a commercially available aqueous fixative. But they neglected to tell me they add 15% ethanol to the commercial solution. I froze all the samples in OCT compound, but they could not be sectioned. I had to melt them all, soak them in several changes of buffer for several hours to remove the OCT and the methanol, then put them in fresh OCT and refreeze them. And that was only 15% alcohol, not 70%! ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] lymph nodes peeling out of OCT
I place all tissues in liquid OCT for at least 15 minutes before freezing. This virtually eliminates the problem of tissue sections separating from the OCT after sectioning. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Precipitating Silver
Yes, it is easy to do. Since silver chloride is insoluble in water, chloride added to a solution containing ionic silver will cause the white compound to precipitate out immediately. It will settle out onto the bottom of the container overnight, or can be filtered out. -Original Message- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of Sheila Haas Sent: Friday, October 29, 2010 1:56 PM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] Precipitating Silver Has anyone heard of precipitating silver out of a solution by adding table salt? I read this somewhere as a means of disposing of silver easily. Any info would be appreciated. Thanks, Sheila Haas Laboratory Supervisor MicroPath Laboratories, Inc. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] Aqua-Mount?
Is Aqua-Mount aqueous mounting medium still available? If so, who sells it? If not, recommendations for a similar product? Thanks Paul ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] dimethyl methylene blue??
Hello, A researcher wants me to do dimethyl methylene blue staining on some cartilage sections. Is anyone familiar with this? Is it just another name for standard methylene blue staining? Or is it actually another dye? If so, where can I get the dye? And, does anyone have a staining protocol they are willing to share? Paul Monfils ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] Microtome Repair - New England Area?
Any recommendations for microtome repairs (preferably on-site), preferably in the MA-RI-CT area? Thanks. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Higgins Ink
I was surprised to see all the references to setting or mordanting of India ink. I have used Higgins ink for many years (No. 4415 Waterproof Drawing Ink). I just blot the tissue, apply the ink, wait a few seconds, blot the excess ink, and drop the tissue back into formalin or alcohol. I have never had a problem with the ink washing off. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Eosin in Processor and iHC
There shouldn't be any problem if you are doing immunoperoxidase staining. If you are doing fluorescence, you will have to be sure you remove all traces of eosin from the tissues since eosin itself is fluorescent. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Trichrome Help
Hi Drew, I don't know precisely what causes this, but I have seen it happen when using a freshly made batch of the dye solution. Also, a very fine whitish precipitate often collects in the bottom of the bottle in which the dye solution is stored, requiring filtration every day before using the solution - but only when the solution is fresh. Once the solution is a couple of weeks old, both problems disappear. Wish I had a better explanation. Paul ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] amnion tissue
I fold the membrane back and forth on a wet piece of lens paper in a petrie dish. This gives me an elongate mass several layers thick and about 1.5 cm in width. I wrap this in lens paper and insert it into a nylon biopsy bag for processing. This holds the whole thing flat. For embedding I unwrap the specimen (which now adheres together pretty well), slice the whole thing right down the center with a scalpel blade, and embed both halves with the cut edge down, right next to each other in the same block. This provides a lot of material to look at microscopically, a dozen or more full length cross sections of the membrane. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] Looking for VEGF and FGF-2 antibodies
I am having a difficult time finding two antibodies I need. Two companies I ordered them from have discontinued them. VEGF and FGF-2 The tissue is human. Monoclonals preferred but at this point I'll use polyclonals if necessary. Does anyone know a vendor who has them? Thanks. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Negative controls for special stains (non-organism)?!?!
I don't see how negative controls for ordinary histochemical procedures would be much help unless they are the same tissue as the test sample. If you are doing a congo red for amyloid plaques in brain, I can see using a known negative brain as a control. But I don't see the point of running a brain section as a negative collagen control when you are staining a lung. What relevance would that have to the test section? ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] RE: Plants in the Histology Lab
I don't know about plants in the lab (never had any) but I recall a problem from years ago. It was a hot summer day and the air conditioning was having problems, so we opened a couple of screened windows in the lab. At the end of the day one of the techs who was reviewing the slides that had just been stained called me over to look at something she couldn't identify. Neither could I. It looked like a little octopus, a central body with several tapering extensions going off in different directions. The whole object was maybe 100 microns wide. A minute later, another one on a different slide. Then three of them on another section. Some on the HE slides, some on the special stains. And the objects themselves were stained! Finally figured out that they were something coming from plants outside the windows, not sure what. They didn't look like pollen, but whatever they were they were blowing in the windows, coming right through the screens, settling on the water baths of the techs cutting sections, and getting picked up on the slides with the tissue sections. I did a wipe of the benchtop next to the water baths and there were hundreds of them. So, no more open windows after that. And I would be careful what plants I brought indoors on that basis. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] Clear Paraffin?
I work in a core histology facility where I receive all kinds of specimens and embedded blocks from many different sources. Occasionally I receive blocks that are embedded in a clear (transparent, not white) embedding wax. Does anyone know what this product is? ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Polarizing filters
The polarizer and analyzer are identical filters, and either of them can be used in either location. One must be between the light source and the slide being viewed. The other must be between the slide being viewed and your eye or camera. I place one filter directly on top of my illuminator. The other is in a filter slide in the microscope column, which can be pushed into the light beam or pulled out of it, but you can also place it directly on top of the slide. You rotate either filter to achieve the polarization effect. I rotate the lower one since the other one is not accessible. These filters cut down the light intensity substantially, so you should use them with maximum brightness of the illuminator, iris diaphram wide open, and with neutral density or any other kinds of filters removed from the light beam, including the blue filter if you normally use one. Polarizing filters can be purchased at any camera store, and some science supply companies sell them. Get good quality glass filters though, not cheap plastic ones. -- From: histonet-boun...@lists.utsouthwestern.edu on behalf of jstaruk Sent: Thursday, September 10, 2009 4:46 PM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] Polarizing filters Does anyone know where I can find the two appropriate filters (lenses) needed to polarize the congo red and Sirius red stains? I have an Olympus CH-2 that needs to be fitted. I understand I need a polarizer lens and an analyzer lens. Are these two different lenses or the same lens, just in different locations on the microscope? Thank you Jim ___ James E. Staruk HT(ASCP) www.masshistology.com www.nehorselabs.com ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] histology for kids
A number of dyes used in histology are also approved for use in foods. These include: Brilliant Blue (FDC Blue #1) Fast Green FCF (FDC Green #3) Erythrosin (FDC Red #3) Tartrazine (FDC Yellow #5) Carmine ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Embeeding frozen tissue in paraffin
I assume you mean the tissue was frozen without fixation, not that you want to put it into paraffin without fixation? No tissue will withstand paraffin processing without fixation. The best way to turn a frozen tissue into a paraffin embedded tissue is to drop the frozen tissue (either plain or in embedding medium, whichever is the case) into formalin while still frozen. Let it thaw and fix in the formalin, using a typical fixation time for a tissue that size, then just process and embed it as you would any tissue. -- From: histonet-boun...@lists.utsouthwestern.edu on behalf of Tomasz Bonda Sent: Friday, May 15, 2009 6:19 AM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] Embeeding frozen tissue in paraffin Hello, is there any good method for embeeding fresh frozen tissue (without any fixation) in paraffin? I would be grateful for ANY suggestions. T. Bonda ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Stain for iodine?
Just a suggestion. Haven't tried it. A classic method for demonstrating starch is exposure to iodine, resulting in a dark purple to black precipitate. I wonder if you could use the technique in reverse, so to speak, and stain the iodine by exposure to a starch solution?? ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Destaining HE slides
Anything mildly basic will quickly destain eosin. Running tap water will do it, usually in 10 minutes or so. 0.1% NaOH or KOH in water or in 70% ethanol will do it quickly. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Finding iron in decalcified sections
The other approach of course would be to avoid decalcification altogether and embed them in methacrylate, provided you are set up to embed and section such blocks. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] When sectioning small long bones in PMMA ....
... such as a mouse femur, do you prefer to orient the bone parallel to the knife edge or perpendicular to the knife edge (or diagonal)? ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] Entamoeba Trophozoites
I haven't checked my email for a few days! Yikes, over 150 messages! But I'll offer this anyway, however late. Entamoeba trophs can easily be demonstrated either in dried fixed smears or in paraffin sections by PAS. Their cytoplasm is loaded with glycogen so they stain very dark. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] Removing PMMA blocks from glass vials
Someone gave me some small PMMA blocks polymerized inside glass scintillation vials. I always use plastic vials. Obviously the vials have to be broken to get the blocks out. Does anyone have some advice on the best way to do this? The guy who brought them said he thought I could use liquid nitrogen, but had no specifics. Any help will be appreciated. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] Von Kossa staining on PMMA sections
The standard Von Kossa silver stain for calcium calls for 20 minutes in the silver nitrate solution under UV light. There is a modified Von Kossa for plastic embedded bone sections, which is identical except it calls for a minimum of 6 hours in the silver nitrate solution under UV. Does anyone know why such a long staining time is recommended? Visually the calcium in the bone sections turns black within 20 minutes, so why is so much additional time needed? Thanks. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
[Histonet] which one first - antigen retrieval or endo peroxidase block?
When doing immunoperoxidase staining on a tissue that requires antigen retrieval, which do you do first - the antigen retrieval or the endogenous peroxidase blocking? Or does it matter? ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] ?bacterial/fungal contamination on slides
Fungi can grow in a number of different aqueous stain solutions. One time a tech brought me a slide she had stained with GMS for fungi, together with the positive control slide she had run. I could see fungi on the test slide but there was no sign of silver staining. The control slide showed positively stained fungi as expected, but also the same unstained fungi seen on the test slide. It turned out a fungus was growing in the aqueous solution of Fast Green we used as a counterstain for the GMS. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
