titer

noun

ti·​ter ˈtī-tər 

variants or chiefly British titre

plural titers

1

: the strength of a solution or the concentration of a substance in solution as determined by titration

… if the analyst is using an oxalic acid solution to titrate a solution of calcium oxide, the titer of the oxalic acid solution would be expressed as its CaO titer, or the weight of CaO that is consumed by 1mL of the oxalic acid solution.

—John Kenkel

2

: a measure of the concentration of a substance (such as an antibody) in a blood sample that is obtained by subjecting the sample to serial dilutions (as with saline) to determine the maximum dilution at which the sample retains a specific activity (such as neutralizing an antigen) and that is often expressed as a ratio (such as 1:200)

I have examples of people who clearly were infected who are antibody negative. They probably have such a low titer of antibody that it's below the level of the cutoff.

—Anthony Fauci

The Blood Center will also ensure that the plasma has high titers of antibodies against the coronavirus.

—John Timmer

also : a test for obtaining a blood titer

—often used before another noun

an antibody titer test

Examples of titer in a Sentence

Recent Examples on the Web

Lab testing determined Misty had a low titer on Valley Fever blood work. —The Arizona Republic, 26 Jan. 2024

At this time, the low titer is suspected to be related to previous exposure rather than an active infection but should be kept an eye on with her future vet. —The Arizona Republic, 26 Jan. 2024

Mice that received the antibodies displayed significantly lower weight loss, more normal pulmonary function, and fewer viral titers in lung tissue than in the control group. —William A. Haseltine, Forbes, 17 Mar. 2023

The implication is that if the vaccine elicits a similar or higher antibody titer, and if people who’ve recovered from Covid-19 are immune from catching the disease again for some period of time, then the vaccine should also provide temporary immunity. —Jeremy Kahn, Fortune, 24 Aug. 2020

Word History

Etymology

French titre title, proportion of gold or silver in a coin, from Old French title inscription, title

First Known Use

1861, in the meaning defined at sense 1

Medical Definition

titer

noun

ti·​ter ˈtīt-ər 

variants or chiefly British titre

ˈtī-tər also ˈtē-

1

a

: the strength of a solution or the concentration of a substance in solution as determined by titration

b

: a measure of the concentration of a substance (such as an antibody) in a blood sample that is obtained by subjecting the sample to serial dilutions (as with saline) to determine the maximum dilution at which the sample retains a specific activity (such as neutralizing an antigen) and that is often expressed as a ratio

a test for toxoplasmosis antibodies yielded a titer of 1:1024

Children with rash had higher antibody titers than those without rash …

—Anne A. Gershon et al., The Journal of the American Medical Association

also : a test for obtaining a blood titer

—often used before another noun

an antibody titer test

2

: the solidifying point of the fatty acids liberated from a fat that is determined by melting the acids in a tube and noting the temperature at which they solidify again on cooling

titered

-ərd 

adjective