All 8 Uses of

positive

in

The Immortal Life of Henrietta Lacks

One month prior to current visit, patient tested positive for gonorrhea.
Chpt 1.1

positive = indicating that a condition was found

When radium was first discovered in the late 1800s, headlines nationwide hailed it as "a substitute for gas, electricity, and a positive cure for every disease."
Chpt 1.3 *

positive = certain

Within weeks of Henrietta's death, Sonny, Deborah, and baby Joe—all between one and four years old—tested positive for TB.
Chpt 2.15 *

positive = indicating that a condition was found

Before beginning his talk, Hayflick stood at the podium and announced that, since WISH cells supposedly tested positive for a genetic marker found only in black people, he'd called his wife during the break to ask if he was, in fact, his daughter's father.
Chpt 2.20

Many of their cell lines tested positive, including the skin cells George Hyatt had transplanted onto a soldier's arm years earlier.
Chpt 2.20

HeLa cells in his lab tested positive for the HPV-18 strain, but zur Hausen requested a sample of Henrietta's original biopsy from Hopkins, so he could be sure her cells hadn't been contaminated with the virus in culture.
Chpt 3.27

The sample didn't just test positive; it showed that Henrietta had been infected with multiple copies of HPV-18, which turned out to be one of the most virulent strains of the virus.
Chpt 3.27

I held a page of the records close to my face to make out the small script, then began reading out loud, " 'This twenty-eight-year-old' ...something ...I can't read the handwriting ...'positive Rh.'†
Chpt 3.34

Definitions:

(1) (positive as in: I'm absolutely positive!)
certain (having no doubt; or used for emphasis)
(2) (positive as in: had a positive effect)
good or beneficial
(3) (positive as in: positive feedback from my boss)
approval or agreement
(4) (positive as in: a positive attitude)
optimistic (expecting or focusing good things); or agreeable
(5) (positive as in: The test came back positive.)
found a condition or substance to be present
(6) (positive as in: a positive number)
greater than zero (of a number)
(7) (meaning too rare to warrant focus)
See a comprehensive dictionary for less common meanings of positive including some in the fields of electricity, physics, chemistry, medicine, philosophy, and grammar. Note that most all senses of positive indicate that something is good or present.