Fanny Angelina Hesse and the Kitchen Jelly That Revolutionized Microbiology

Fanny Angelina Hesse suggested replacing gelatin with agar in Robert Koch's bacteriological laboratory during the early 1880s to prevent culture mediums from liquefying at incubation temperatures.

Gelatin melted at 37 degrees Celsius and was digested by certain bacteria enzymes, collapsing experimental structures and merging colonies.

Agar, a complex polysaccharide extracted from red algae cell walls containing agarose and agaropectin, remained firm in warm weather and solved foundational problems in microbiology.