| Description | Background information Annexins are a family of calcium-dependent phospholipid-binding proteins that preferentially bind phosphatidylserine (PS). Under normal physiologic conditions, PS is predominantly located in the inner leaflet of the plasma membrane. Upon initiation of apoptosis, PS loses its Background information Annexins are a family of calcium-dependent phospholipid-binding proteins that preferentially bind phosphatidylserine (PS). Under normal physiologic conditions, PS is predominantly located in the inner leaflet of the plasma membrane. Upon initiation of apoptosis, PS loses its asymmetric distribution across the phospholipid bilayer and is translocated to the extracellular membrane leaflet marking cells as targets of phagocytosis. Once on the outer surface of the membrane, PS can be detected by fluorescently labeled Annexin V in a calcium-dependent manner.In early-stage apoptosis, the plasma membrane excludes viability dyes such as propidium iodide (PI), 7-AAD. These cells will stain with Annexin V but not a viability dye, thus distinguishing cells in early apoptosis. However, in late stage apoptosis, the cell membrane loses integrity thereby allowing Annexin V to also access PS in the interior of the cell. A viability dye can be used to resolve these late-stage apoptotic and necrotic cells (Annexin V, viability dye-positive) from the early-stage apoptotic cells (Annexin V positive, viability dye-negative).We offer recombinant Annexin V conjugated to a numerous fluorophores, as well as an Annexin V biotin conjugate which can be detected with fluorophore-labeled streptavidin. By binding to PS, fluorophores labeled Annexin V can be used to detect and quantify apoptotic cells via flow cytometry or fluorescence microscopy. The excitation and emission maxima of the Annexin V conjugates are summarized in the following table.Cat.No.Ex/Em (nm)Formatrp226056NABiotinrp225999401/422AF405rp226057490/525AF488rp226060650/668AF647rp226002681/704AF680rp226003752/776AF750rp226053498/517FITCrp226004410/455Pacific Bluerp226006647/665Cy5rp226054650/660APCrp226055565/575PErp226058565/670PE-Cy5rp226059565/774PE-Cy7Precautions1. Please try to avoid light when using to slow down the quenching of fluorescence.2. Propidium Iodide Solution is toxigenic and mutagenic; handle with care.3. Due to the calcium dependence of the Annexin V:PS interaction, it is critical to avoid buffers containing EDTA or other calcium chelators during Annexin V experiments.Instruction for use1. Dilute 10X Binding Buffer (A1372288) to 1X using distilled water (1 mL 10X Binding Buffer + 9 mL ddH2O).2. Wash cells twice with cold PBS and then resuspend the desired amounts of cells in Annexin V Binding Buffer at a concentration of 1.0-5.0 x 106 cells/mL.3. Add 5 µL of Annexin V-AF405 to 100 µL of the cell suspension. Stain with a viability dye, such as PI (P1373641; P1372285), 7-AAD (A1372406), or DAPI (D1372407) dyes, if desired.4. Gently vortex the cells and incubate for 10 min at RT (25°C) in the dark.5. Add 100 µL of 1X Binding Buffer to each assay. Analyze by flow cytometry within 1 hr... Read More | Inquire | Inquire | Biochemical Test:SDS-PAGE (purity > 80%); Western blot with patient sample.Calculated Isoelectric Point:pH 6.64 | Ribonuclease T1 is an endoribonuclease, highly specific for the cleavage of RNA or deaminated RNA between guanosine 3'-phosphate residues (or inosine 3'-phosphate) and the 5'-OH residues of adjacent nucleotides with the formation of the corresponding intermediate 2', 3'-cyclic phosphates. It cleavesRibonuclease T1 is an endoribonuclease, highly specific for the cleavage of RNA or deaminated RNA between guanosine 3'-phosphate residues (or inosine 3'-phosphate) and the 5'-OH residues of adjacent nucleotides with the formation of the corresponding intermediate 2', 3'-cyclic phosphates. It cleaves single-stranded RNA releasing oligonucleotides from the guanosine 3'-phosphate termini. The enzyme has a molecular weight of 11 kDa. The optimum pH is 7.5. RNase T1 is inhibited by Ag+, Zn2+, Cu2+, and Hg2+ at 1 X 10-3 M. The stimulatory effects of both histidine and EDTA are attributed to chelation of contaminating inhibitor cations. The enzyme assay is essentially the method of Egami et al., Prog. in Nucleic Acid Res. and Molec. Biol., III, 59 (1964) based upon the release of acid soluble oligonucleotides following the digestion of yeast RNA.Ribonuclease T1 (RNase T1) from Aspergillus oryzae is used to digest denatured RNA prior to sequencing and is used for protein folding studies. ApplicationRibonuclease T1 has extensive applications in molecular cloning and DNA sequencing. Because of its specificity it has been a commonly used cleavage enzyme for the determination of structure, nearest neighbor frequencies, and RNA sequencing. The enzyme has further application in the preparation of nucleoside 2',3'-cyclic phosphates, the synthesis of oligonucleotides, and the removal of RNA from DNA preparations. The enzyme is also used as a non-mammalian source of RNase in various applications... Read More |