Flow cytometer analyzer
This apparatus has recently been acquired by TWB to complete the “flow cytometry” service offer. It is located on the Biotransformation & culture platform, under the responsibility of Delphine LESTRADE. The flow cytometer MACSQuant® VYB (Miltenyi Biotec) is a
cytometer-analyzer enabling an individual, quantitative and qualitative characterization of fluorescence optical properties of cells in suspension: microbial cells or lower eukaryotic or microalgae cells for example. It is an automated instrument, equipped with a sample changer, which
can analyze up to 10 000 events per second. The flow cytometry technique enables the high-speed streaming of cells. Each particle can be excited by one or several lasers. Many detectors placed at different angles provide information in terms of size, structure, and fluorescent content for each cell.
The MACSQuant VYB is equipped with three monochromatic excitation lasers, ten optical detection channelsand an intuitive software to facilitate a quick and simple cellular analysis. This instrument is versatile for
phenotypic and/ or functional analyses using fluorescent reporterssuch as dyes, fluorescent proteins or antibodies coupled to fluorochromes. It is configured with a 561nm laser for an improved and more sensitive analysis of the fluorescent proteins located in the yellow / green excitation range. The “sample changer” platform is automated and flexible, thus enabling the sequence analysis of samples packed in 5 mL, 15 mL, or 50mL tubes but also in 96-well plate. The sample injection is performed through a 500 mL Hamilton syringe. Since the sample volume is precisely known, it is possible to obtain an
enumeration of the different cell populationsobserved. The concentration will be given in number of cells per mL with a +/- 2% accuracy.
The cytometer MACSQuant® VYB Miltenyi Biotec (Credits: TWB / B. Hamousin)
The characteristics of the MACSQuant VYB cytometer are
- 3 monochromatic lasers: 405, 488 and 561nm
- 10 detection channels: including 2 relating to cell size (FSC) and cellular complexity (SSC) + 8 dedicated to fluorescence detection (see optical diagram Fig 1 below)
- Minimum volume of analysis: 25µL
- resolution: 0.5 µm
It is possible
- to use the sample changer for a fully automated analysis (tube changer 5 ml; 15ml; 50ml and 96-well plate changer)
- to perform a labeling with incubation management before the analysis and using up to 4 different reagents
- to maintain an analysis temperature at 4°C for 4h
- to analyze cells between 0.5 µm and 150 µm in size.
Examples of typical applications
- Direct count of microorganisms
- Detection and count of viable, viable but non-cultivable, and dead microorganisms
- Quantification of reporter genes
- Characterization of physiological data: intracellular pH, oxidative stress, membrane fluidity, energy charge, membrane potential.
- Fine analysis of microbial catalysts for process improvement
- Cell bank screening
- Assessment of the populations in microbial consortia.
Fig. 1: Diagram of the fluorescence detection optical bench of MACSQuant VYB (Miltenyi Biotec)
