ISO 19040-1:2018 水質 — 水と廃水のエストロゲンポテンシャルの決定 — Part 1: 酵母エストロゲンスクリーニング（Saccharomyces cerevisiae） | ページ 5

3.1

blank replicate

additional replicate that contains no test organism, but is treated in the same way as the other replicates of a sample

[SOURCE:ISO 10872:2010, 3.5]

3.2

culture medium

nutrients presented in a form and phase (liquid or solidified) which support microbiological growth

[SOURCE:ISO 6107‑6:2004, 24]

3.3

dilution level

D

denominator of the dilution coefficient (using the numerator 1) of a mixture of water or waste water with dilution water as integral number

Note 1 to entry: For undiluted water or waste water, this coefficient per definition is 1→1. The corresponding and smallest possible value of D is 1. In this document, the arrow indicates the transition from initial total volume to final total volume.

[SOURCE:ISO 6107‑6:2004, 28]

3.4

dilution water

water added to the test sample to prepare a series of defined dilutions

[SOURCE:ISO 20079:2005, 3.7]

3.5

50 % effect concentration

EC₅₀

concentration of a compound which causes 50 % of an effect

Note 1 to entry: In the sense of this document, the EC₅₀ is the concentration of a compound which induces 50 % of the maximal reporter gene activity which can be achieved by this compound.

3.6

field blank

container prepared in the laboratory, using reagent water or other blank matrix, and sent with the sampling personnel for exposure to the sampling environment to verify possible contamination during sampling

[SOURCE:ISO 11074:2015, 4.5.3]

3.7

induction rate

quotient of the mean signal measured after exposure to a dose of the test sample or with a positive control, and the mean signal measured for the negative control using the same experimental conditions

[SOURCE:ISO 6107‑6:2004, 43, modified — “corrected absorbance” replaces “mutant colonies”; “wells” replaces “corresponding plates”, “quotient” replaces “difference”.]

3.8

inoculum

fraction of a culture of microorganisms used to start a new culture, or an exponentially growing preculture, in fresh medium

[SOURCE:ISO 6107‑6:2004, 44]

3.9

limit of quantification

LOQ

lowest value of a determinant that can be determined with an acceptable level of accuracy and precision

[SOURCE:ISO 15839:2003, 3.18]

3.10

lowest ineffective dilution

LID

lowest dilution within a test batch which does not show any effect, i.e. no statistically significant increase in the reporter gene activity compared with the negative control

[SOURCE:ISO 11350:2012, 3.4, modified — “increase in the reporter gene activity” replaces “increase in the number of revertant wells”.]

3.11

negative control

dilution water without test sample

[SOURCE:ISO 6107‑6:2004, 51]

3.12

overnight culture

culture started late in the afternoon and incubated overnight to be ready during the following morning for purposes such as the inoculation of a preculture

Note 1 to entry: The procedure for the overnight culture is described in 9.2.

[SOURCE:ISO 6107‑6:2004, 54, modified — deleted:"usually about 16 h".]

3.13

reference compound

compound with one or more property values that are sufficiently reproducible and well established to enable the calibration of the measurement method

[SOURCE:ISO 7405:2008, 3.6, modified — “compound” replaces “material”; “the calibration of the measurement method” replaces “use of the material or substance for the calibration of an apparatus, the assessment of a measurement method or for the assignment of values to materials”.]

3.14

reporter gene activity

quantitative activity of a gene attached to the promoter sequence of another gene

3.15

stock culture

culture of a strain of organisms maintained under conditions to preserve original features such as nucleotide sequences

[SOURCE:ISO 6107‑6:2004, 87]

3.16

test sample

undiluted, diluted or otherwise prepared portion of a sample to be tested, after completion of all preparation steps such as centrifugation, filtration, homogenization, pH adjustment and determination of ionic strength

[SOURCE:ISO 6107‑6:2004, 92]