FASER Kits

Enlightening: brightens up dim fluorescence signals
Clear-cut: accurately discriminates cell populations through increased sensitivity
No-compromise: use the same epitope for cell sorting and analysis

Description

The FASER Kits an be used to amplify weak fluorescence intensity resulting from staining of low-expressed antigens, the use of low-affinity antibodies, or immunomagnetic and fluorochrome-conjugated antibody labeling of cells via the same epitope. Furthermore, increasing the fluorescence intensity simplifies the flow cytometric discrimination of labeled and non-labeled cell fractions. The FASER Kits can also be used in combination with Anti-FITC, Anti-PE or Anti-APC MicroBeads for the enhancement of weak magnetic labeling.

Details

The FASER (Fluorescence Amplification by Sequential Employment of Reagents) Kits – FITC, PE, and APC were developed to increase the fluorescence intensity of cells labeled with virtually any antibody conjugated to FITC (fluorescein-isothiocyanate), PE (R-phycoerythrin) or APC (allophycocyanin). Fluorescence intensity is amplified by the sequential addition of two reagents: The fluorochrome-specific Activator (Reagent 1) and the fluorochrome-conjugated Enhancer (Reagent 2) (see fig. 3). For further enhancement of fluorescence intensity, the sequential addition of reagents can be performed as often as required. The FASER Kits do not affect direct staining with other fluorochrome-conjugated antibodies or MACS^® MicroBeads but should not be used in combination with biotin-conjugated antibodies. They are suitable for fresh or formaldehyde-fixed cells in suspension of any type or any species. Analysis is performed by flow cytometry.

Figure 1

Human PBMCs were stained with CD19-FITC. The FITC fluorescence was increased by two rounds of amplification using the FASER Kit – FITC. The mean fluorescence intensity of the CD19⁺ cell population is amplified in the first round of amplification by a factor of six and in the second round by a factor of nine compared to the non-amplified staining.

Before use of the FASER Kit – FITC

1^st Amplification round using the FASER Kit – FITC

1<sup>st</sup> Amplification round using the FASER Kit – FITC

2^nd Amplification round using the FASER Kit – FITC

2<sup>nd</sup> Amplification round using the FASER Kit – FITC

The mean fluorescence intensity of the CD19⁺ cell population is amplified in the first round of amplification by a factor of 6 and in the second round by a factor of 9 compared to the non-amplified staining.

Figure 2

PBMCs from rhesus monkey were stained with CD8-FITC and Anti-CCR7-PE. PE-fluorescence was amplified by using the FASER Kit-PE.
(Data were kindly provided by Dr. Paula Acierno, Beth Israel Deaconess Medical Center, Boston, USA.)

Before use of the FASER Kit – PE

1^st Amplification round using the FASER Kit – PE

1<sup>st</sup> Amplification round using the FASER Kit – PE

2^nd Amplification round using the FASER Kit – PE

2<sup>nd</sup> Amplification round using the FASER Kit – PE

Figure 3

Principle of Fluorescence Amplification by Sequential Employment of Reagents (FASER).