PKmem 555

$0.00
SKU
CY-SC062

PKmem 555 is a bright, non-phototoxic & non-toxic plasma membrane probe based on the PKmem™ dyes developed by the lab of Zhixing Chen at Peking University1). PKmem 555 labels the plasma membrane in live cells with very high specificity. The unique and unmatched feature of PKmem 555 is its extremely low phototoxicity, due to the presence of the intramolecular triplet quencher cyclooctatetraene (COT) group. It allows to perform long term live cell imaging of the plasma membrane without damaging the cells. PKmem 555 does not require any genetic manipulation, transfection or overexpression of fluorescent proteins. PKmem 555 enables multicolor imaging with SPY505, SPY595, SPY650, SPY700, SiR or GFP. PKmem 555 can be imaged with a standard TMR or Cy3 filterset. It can be used for widefield, confocal, or SIM imaging in living cells and tissue. Contains 1 vial of PKmem 555 (lyophilized).

 

Absorbance Maximum λabs (MeOH)

 556 nm

Fluorescence maximum λfl (MeOH)

 572 nm

Works on fixed cells?

 yes

Probe quantity

100 stainings*

Fluorescence lifetime

 n.d.

STED depletion wavelength

 600 nm

Shipping

 room temperature

Storage

 -20°C

 

Cells Stained with PKmito RED

mESC_PKmem555_PKmitoDEEPRED

PKmito RED

PKmem555_HeLa

If you have any questions concerning this product, please contact our Technical Service department at tservice@cytoskeleton.com

Q1. What is STED microscopy and how does it work?

A1. STED microscopy stands for Stimulated Emission Depletion microscopy.  It is one type of super resolution microscopy which allows the capture of images with a higher resolution than conventional light microscopy which is constrained by diffraction of light.  STED uses 2 laser pulses, one is the excitation pulse which excites the fluorophore, causing it to fluoresce.  The second pulse, referred to as the STED pulse, de-excites the fluorophore via stimulated emission in an area surrounding a central focal spot that is not de-excited and thus continues to fluoresce.  This is accomplished by focusing the STED pulse into a ring shape, a so-called donut, where the center focal spot is devoid of the STED laser pulse, conferring high resolution to the fluorescent area (Fig. 1; see Ref. 1 for more details on STED microscopy).

fig1-faq

Figure 1. STED microscopic image of microtubules labeled with SiR-tubulin in human primary dermal fibroblasts.

Q2: Are the SPY™ probes stable at room temperature?

A2: Yes, the probes are stable at room temperature for a few days.  However, it strongly depends on the probe and the solvent.  Thus, it is recommended to store all of the probes or solutions at –20°C.

 

References

1. Liu Tianyan et al. “Multi-color live-cell STED nanoscopy of mitochondria with a gentle inner membrane stain” PNAS (2022):119 (52).
2. Yang, Zhongtian, et al. “Cyclooctatetraene-conjugated cyanine mitochondrial probes minimize phototoxicity in fluorescence and nanoscopic imaging.” Chemical science 11.32 (2020): 8506-8516.