The Thermo Scientific VitroEase Apoferritin Standard is a highly validated pure protein for use as a quality control sample for cryo-electron microscopy single particle analysis.

Features of the VitroEase Apoferritin Standard include:
• Positive control sample—apoferritin protein production optimized and validated for use in cryo-EM grid preparation and analysis
• Rigorously tested—high-quality, consistent protein standard documented via lot-specific certificates of analysis
• Convenient—ready-to-use format with each single-use vial sufficient for 5–6 grid preparations

Protein sample grid preparation is a major bottleneck in cryo-electron microscopy (cryo-EM) single particle analysis (SPA), often requiring days or even weeks to optimize. The VitroEase Apoferritin Standard has been designed specifically to meet the stringent needs for high protein purity, minimal protein aggregation, and intact protein structure. Apoferritin, a 24-subunit protein (474 kDa), is considered the gold standard for cryo-EM SPA, and this standard is fit for use as a comparison for success for new users or as quality control for expert users.