Comparar métodos

	Ensaio Transwell	Ensaio Live/Dead
Área	Biomateriais	Biomateriais
Família	Process / pipeline	Process / pipeline
Ano de origem	1962	2000
Autor original	Stephen Boyden	Invitrogen/Molecular Probes
Tipo	Migration/invasion assay	Dual-dye viability assay
Fonte seminal	Boyden, S. (1962). The chemotactic effect of mixtures of antibody and antigen on polymorphonuclear leucocytes. Journal of Experimental Medicine, 115(3), 453-466.	Molecular Probes (2004). LIVE/DEAD Viability/Cytotoxicity Kit user guide. Invitrogen Corporation.
Outros nomes	Boyden chamber assay, chemotaxis assay, invasion chamber assay	calcein-AM/propidium iodide, SYTO/PI staining, fluorescent viability stain
Relacionados	4	4
Resumo	The Transwell assay (also called the Boyden chamber assay after its originator Stephen Boyden) is a quantitative method for measuring cell migration and invasion in response to chemical gradients or through matrix barriers. The assay uses a membrane insert with defined pore size suspended in a multi-well plate: cells are placed in the upper chamber, a chemoattractant is placed in the lower chamber, and cells that successfully migrate through the pores accumulate in the lower chamber, where they can be counted or visualized. Variants that coat the insert with matrix proteins (Matrigel, collagen) enable measurement of invasion capacity. The Transwell assay is a gold-standard method in cell biology for evaluating cell motility, tumor metastatic potential, and the effects of growth factors and inhibitory compounds.	The Live/Dead assay is a fluorescence-based method for simultaneously identifying live and dead cells using two complementary dyes. The assay combines calcein-AM (or SYTO fluorophores), which generates bright green fluorescence in living cells with intact esterase activity, with propidium iodide (PI), which produces red fluorescence in dead cells with compromised membrane integrity. Commercially developed by Molecular Probes and now part of Thermo Fisher's portfolio, the Live/Dead kit is widely used to evaluate cell viability on biomaterial scaffolds, in tissue constructs, and following drug or toxin exposure.