As a noun serum

is serum.

As an adjective seronegative is

.

As adjectives the difference between negative and seronegative

is that negative is while seronegative is .

As a noun pathogen

is (pathology|immunology) any organism or substance, especially a microorganism, capable of causing disease, such as bacteria, viruses, protozoa or fungi microorganisms are not considered to be pathogenic until they have reached a population size that is large enough to cause disease.

As an adjective seronegative is

.

As a noun HIV

is initialism of human immunodeficiency virus.

As an adjective seronegative is

(of blood serum) Testing negative for a given pathogen, especially HIV.

Seronegativity is a derived term of seronegative.

As an adjective seronegative is

.

As an adjective seropositive

is .

As a verb seroconvert is

to become seropositive: to be infected by a bloodborne pathogen.

As verbs the difference between infect and seroconvert

is that infect is to bring into contact with a substance that causes illness (a pathogen) while seroconvert is to become seropositive: to be infected by a bloodborne pathogen.

As an adjective infect

is (obsolete) infected.

As an adjective bloodborne

is (medicine) usually of a pathogen, carried in the bloodstream and other body fluids.

As a verb seroconvert is

to become seropositive: to be infected by a bloodborne pathogen.

As a noun pathogen

is (pathology|immunology) any organism or substance, especially a microorganism, capable of causing disease, such as bacteria, viruses, protozoa or fungi microorganisms are not considered to be pathogenic until they have reached a population size that is large enough to cause disease.

As a verb seroconvert is

to become seropositive: to be infected by a bloodborne pathogen.

As nouns the difference between precursor and androstenedione

is that precursor is that which precurses, a forerunner, a predecessor, an indicator of approaching events while androstenedione is a steroid hormone produced in the adrenal glands and the gonads, chemical formula c₁₉h₂₆o₂; the common precursor to both male and female sex hormones.