Technical Support Articles

How should I resuspend and aliquot the PTMScan® LysC Protease #84748?

To resuspend the PTMScan® LysC Protease #84748, we recommend allowing the vial to equilibrate at room temperature for a few minutes after removing from the -20C freezer. Next, spin the vial at 1,0...

Why do I need to use the three buffers in the Cell Fractionation Kit #9038?

Each buffer in the Cell Fractionation Kit #9038 contains detergents to help isolate different cellular fractions. The Cytoplasmic Isolation Buffer (CIB) contains a non-ionic detergent used as a cell p...

Can you provide data that confirms the specificity of your Raptor (24C12) Rabbit mAb #2280?

The specificity of our Raptor (24C12) Rabbit mAb #2280 has been confirmed by siRNA in the following papers:

PMID: 28648777 (https://pubmed.ncbi.nlm.nih.gov/28648777/) Figure 2B

PMID: 249...

Do you have human-reactive antibodies available for SignalStar™ Multiplex IHC?

How are the SignalStar™ Multiplex IHC Kits & Reagents validated?

The “classic” PTMScan® kits that use agarose beads and the PTMScan HS kits that use magnetic beads are both designed for a single PTM peptide enrichment. The nature of the acidic elution step, which l...

When comparing my SignalStar™ staining to the chromogenic staining on a serial section, I see more positive cells. How do I know if this excess staining is correct?

During the course of optimization, we’ve found that fluorescent staining may show higher %-positivity than chromogenic staining. To ensure any excess staining is specific, confirm that the correct sub...

Should I be concerned that my Concanavalin A beads "clump together" in some of my CUT&RUN experiments?

The Concanavalin A beads can clump together rather easily, especially when the cells become lysed. To avoid this, make sure your cells are healthy and be sure to treat them very gently during the cell...

How long after the completion of staining can I wait to image my slides when performing a SignalStar™ Multiplex IHC assay?

For Imaging Round 1, the staining should show robust signal when imaged up to 8 hours post completion of staining. For Imaging Round 2, imaging should be performed as close to the completion of staini...

Does your CUT&RUN Assay Kit work with isolated nuclei?

Our CUT&RUN Assay Kit is optimized for use with whole cells and works with a large number of cell lines, both adherent and suspension. While it is not typically necessary to pre-isolate cell nucle...

Is PTMScan® compatible with SILAC?

PTMScan® is compatible with the use of stable isotope labeling using amino acids in cell culture, or SILAC. The incorporation of heavy stable isotopes has no effect ...

What is the species reactivity of the SUMO remnant PTMScan® kits that utilize WaLP for peptide digest?

Wild type alpha-lytic protease (WaLP) is a serine endopeptidase that cleaves at the carboxyl terminal side of amino acids alanine, serine, threonine, and valine.

WaLP recognizes and cleaves SUM...

What is the best way to choose an antibody for my CUT&RUN assay if I cannot find a CUT&RUN validated antibody for my target protein?

When selecting an antibody for use in CUT&RUN, we recommend starting with a ChIP or ChIP-seq-validated antibody; however, we have found that not all ChIP-validated antibodies work in the CUT&am...

How stable is the Senescence β-Galactosidase Staining Kit #9860 after multiple freeze/thaws?

We are confident that the Senescence β-Galactosidase Staining Kit #9860 will continue to perform as expected up to at least 3 freeze/thaw cycles. We recommend aliquoting your reagents into single use ...

What is an appropriate positive control to include in this SignalStar™ assay? Are multiple controls necessary?

Any tissue shown to be positive for each marker via chromogenic IHC can serve as a positive control tissue for a SignalStar™ assay. Each target will therefore require a positive control, which may som...

Do you have mouse-reactive antibodies available for SignalStar™ Multiplex IHC?

Can I use primers from the Illumina Nextera Library preparation system or design my own primers to amplify the DNA library generated from the CUT&Tag Assay Kit #77552??

Yes, you can use primers from the Illumina Nextera Library preparation system or self-designed primers to amplify the DNA library generated from the CUT&Tag DNA using the CUT&Tag Assay Kit #77...

My items say to store at -20°c but they were shipped in an envelope. Is it ok to use?

Yes, it is safe to use these items. Since 2003, CST has been shipping antibodies at room temperature when possible to reduce waste from packing materials. All CST antibodies are stability tested by ex...

Do I need to optimize the SignalStar™ Multiplex IHC Kits & Reagents for the type of tissue I’m using?

The SignalStar Multiplex IHC kits and reagents have been optimized with respect to fluorophore pairing and order of antibodies. As tissues vary in quality and expression level of biomarkers, increasin...

Which β-actin antibody do you suggest for immunofluorescence-immunocytochemistry (IF-IC) in human samples?

We have several antibodies for detecting β-actin that are validated for IF-IC with human samples. These include: