Calcein (solution)

Calcein (solution) (Fluorexon (solution)) is a fluorescent dye and self-quenching probe, used as an indicator of lipid vesicle leakage, and also as a complexometric indicator for titration of calcium ions with EDTA, and for fluorometric determination of calcium. Calcein cannot directly cross the intact cell membrane of a living cell, unlike Calcein-AM (HY-D0041) which is cell-permeable. Calcein can also be used as a model drug for evaluating efficiency and bioavailability of drug delivery systems^[1][2].
Solvent and concentration: DMSO: 2 mM
The 1 mL volume is defined as the base specification. All larger sizes correspond to incremental volumes of this base. In Vitro: Description: Calcein is a fluorescent probe with yellow green fluorescence, it can be used to determine labile iron pool and measure the Fe(III)-binding affinity with ligands^[3].
Guide (The following is our recommended protocol. This protocol is only a guide and should be modified according to your specific needs).
1. Solution preparation^[3]
1.1 Preparation of working solution
Dilute to 0.5 μM with PBS or cell culture medium.
Note: The working solution should be prepared and used immediately. Keep it away from light.

2. Cell staining
2.1 Cells (10⁶/mL) are loaded by incubation with 20 μM Fe(II) for 2 h at 37°C. 2.2 Cells are collected by centrifugation (1000 rpm; 5 min) and Calcein (0.5 μM) is directly injected into the cells via microinjection for staining (5-15 mins). 2.3 Wash cells for twice by D’hanks buffer (pH 7.4). 2.4 The fluorescence is monitored by both flow cytometry and a confocal laser scanning microscope.