Plant Agar — 500 g

Plant-grade agar is the standard gelling agent for solidifying tissue culture media, used at 0.6–1.0% (w/v). Purified from red algae, plant-grade agar has lower phenolic impurities than food-grade alternatives, reducing interference with sensitive cultures. Dissolve by stirring on moderate heat, then autoclave at 121°C for 15 minutes. Cool to ~55°C before adding heat-sensitive components such as growth regulators or gibberellins.