Wheat Germ Agglutinin, Alexa Fluor™ 594 Conjugate, 5 mg - FAQs

View additional product information for Wheat Germ Agglutinin (WGA) - FAQs (W56133, W56132, W56134, W32466, W32465, W11263, W32464, W11262, W11261, W834, W849, W21405, W21404, W7024, Q12021MP, W6748)

11 product FAQs found

我注入了荧光示踪剂,但在组织固定并切片后无法检测到它,哪个环节出了问题?

•请确认您所用的示踪剂交联到蛋白质上,或具有用于固定的伯胺——酰肼、赖氨酸可固定葡聚糖或蛋白质偶联物皆可。
•使用醛类固定剂交联示踪剂上的胺基。
•注入更大量或更高浓度的示踪剂。示踪剂通常注射1-20%浓度(10 mg/mL或更高)。
•确认您使用正确的荧光滤光片进行检测。您可吸取少量未稀释的示踪剂储液滴一滴到载玻片上,然后在显微镜下使用您所需的滤光片观察测试。这可验证示踪剂荧光是否可以被检测到,以及荧光显微镜的滤光片是否工作正常。
•回顾组织固定和处理步骤,确认是否存在可能影响示踪剂的试剂或处理步骤。

你们有只能逆向示踪的示踪剂吗?

麦胚凝集素和霍乱毒素偶联物可以用于逆向示踪。它们在某些应用中可能会有一些顺向示踪。选择指南可以在这里找到(https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-tracing-tracking-and-morphology/neuronal-tracing/protein-conjugates.html)。

我该如何为自己的试验选择示踪对象?

要考虑的因素有示踪对象的大小、给样方式(注射,直接上样到组织等),示踪对象是否需要固定。以下链接详细介绍了我们提供的各类神经元示踪剂的详细信息以及选择方法:

•神经元示踪(https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-tracing-tracking-and-morphology/neuronal-tracing.html)
•选择示踪剂(https://www.thermofisher.com/us/en/home/references/molecular-probes-the-handbook/fluorescent-tracers-of-cell-morphology-and-fluid-flow/choosing-a-tracer.html)
•成像分析(http://assets.thermofisher.com/TFS-Assets/BID/Reference-Materials/bioprobes-50-journal.pdf)

我想标记细胞膜,但可选的染料有多种,该如何选择?

如果进行活细胞成像,CellVue和CellMask 质膜染色剂染色最均匀,被细胞内吞的速度最慢。如果想固定和通透细胞(如进行抗体标记),这种产品并不是最佳选择。麦胚凝集素(WGA)偶联物也能标记活细胞,或者甲醛固定的细胞。它们可以在随后的去垢剂(如TritonX-100)通透处理后保存下来。但如果细胞已经进行通透处理,WGA也会标记内部结构。因此,如果细胞已通透,则只能使用靶向质膜蛋白的抗体。亲脂性花青染料(如DiI)会标记活细胞的所有膜结构,而不仅仅是细胞质膜。此网页(https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-structure/plasma-membrane.html)的内容可帮助您进行选择。

My cells are very sensitive and need to be kept in media as much as possible. Is it possible to label the plasma membrane with fluorescent wheat germ agglutinin (WGA) in media instead of buffer?

Yes. Although labeling in buffer (such as Hank's Buffered Saline Solution) is slightly better for brightness and lower non-cell background, media can be used. Do a concentration range to dertermine optimal conditions, since the WGA may potentially bind media components to some extent, slightly decreasing your specific labeling intensity.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

Can I use CellMask Plasma membrane stains or Alexa Fluor dye labeled wheat germ agglutinin to label the plasma membrane of my paraffin sections?

No. For paraffin sections, there are few options due to the delipidation of the membranes by solvents used in the deparaffinization steps. The only good option is to use an antibody against a plasma membrane protein.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

I want to label Golgi bodies in my fixed cells. Is a dye-conjugated lectin like wheat germ agglutinin or concanavalin A a good choice?

No. Those lectins have been shown to label Golgi in fixed and permeabilized cultured cells, but the selectivity is cell type dependent. Usually you wind up with other structures labeling as well, such as endoplasmic reticulum. The only guaranteed way to specifically label Golgi in already fixed cells is to use an antibody for a Golgi-specific antigen.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

I injected a fluorescent tracer, but cannot detect it after tissue is fixed and sectioned. What am I doing wrong?

Confirm that the tracer you are using crosslinks to proteins or has a primary amine for fixation-either a hydrazide, lysine fixable dextran, or a protein conjugate.
Use aldehyde-based fixatives to cross link the amines on the tracer.
Inject a larger amount or higher concentration of the tracer. Tracers are generally injected at 1-20% concentrations (10 mg/mL or higher).
Confirm that you are using the correct fluorescent filter for detection. You can perform a spot test by pipetting a small amount of the undiluted stock solution of the tracer onto a slide, then view under the filter you are using on your microscope. This will confirm if the tracer fluorescence can be detected and the fluorescent microscope filter is working properly.
Review tissue fixation and handling procedures to confirm if any reagents or processing procedures could be affecting the tracer.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

Do you have a tracer that will only transport retrograde?

Wheat germ agglutinin and cholera toxin conjugates have been used for retrograde tracing. They may have some anterograde tracing in some applications. A selection guide can be found here (https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-tracing-tracking-and-morphology/neuronal-tracing/protein-conjugates.html).

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

How do I know which tracer to choose for my experiment?

Factors to consider are size of tracer, method of delivery (injection, direct application to tissue, etc.), and if the tracer needs to be fixable. Here are some links to details about the various classes of neuronal tracers we offer and how to choose between them:

Neuronal Tracing (https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-tracing-tracking-and-morphology/neuronal-tracing.html)
Choosing a Tracer (https://www.thermofisher.com/us/en/home/references/molecular-probes-the-handbook/fluorescent-tracers-of-cell-morphology-and-fluid-flow/choosing-a-tracer.html)
Imaging Analysis (http://assets.thermofisher.com/TFS-Assets/BID/Reference-Materials/bioprobes-50-journal.pdf)

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

I want to label the plasma membrane of my cells, but there are several dyes to choose from. Which one should I use?

For live-cell imaging, the CellVue and CellMask Plasma Membrane Stains are the most uniform and the slowest to be endocytosed. However, they are not the best choice if you wish to fix and permeabilize your cells, such as for antibody labeling. Wheat germ agglutinin (WGA) conjugates are also able to label live cells, or can label already formaldehyde-fixed cells. They can survive subsequent permeabilization with detergents, such as Triton X-100. If cells are already permeabilized, WGA will label internal structures as well. Thus, only an antibody against a plasma membrane protein can be used if cells are already permeabilized. Lipophilic cyanine dyes, such as DiI, will label all cell membranes in live cells, not just plasma membranes, if left on live cells for extended periods. Following page will help you choose (http://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-structure/plasma-membrane.html).

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.