Elizabeth Blackwell. (b. 1821, Bristol, England; d. 1910, Sussex, England) In 1849, Elizabeth Blackwell became the first woman to receive a medical degree in the United States. The English-born physician opened the field for other women while founding important medical institutions such as the New York Infirmary for Women and Children in 1857, and the National Health Society in 1871.
An assay is an investigative (analytic) procedure in laboratory medicine, pharmacology, environmental biology and molecular biology for qualitatively assessing or quantitatively measuring the presence or amount or the functional activity of a target entity (the analyte).
Assay is the quantitative determination of the amount of a component in a sample. Purity is the determination of the impurities in the sample. It can be quantitative, semi-quantitative or qualitative. For example : if you dissolve 4 grams of compound A (with no impurities in it) in 6 grams of water, you get a solution of compound A with 100% purity and 40% assay.