API 20E Test Essay

API 20E test
API 20 E or analytical profile index 20 E is a standard bio chemical test used to identify the presence of bacteria using 21 miniaturized bio chemical chambers in a slide card. All the reagents in the cupule are found in the dehydrated form. Upon incubation followed by inoculation with bacterial sample, there will be spontaneous color changes with or without addition of extra reagent.

Material and equipment
I. Agar plates of bacterial species
II. Sterile Pasteur pipette
III. API 20 E test strips
IV. API 20 E test strips incubation tray
V. Inoculation loop
VI. Bunsen burner
VII. API 20 E analytical profile index
VIII. McCartney bottle
Chemical and reagents
1. 0.85 % Sodium Chloride solution
2. Sterile mineral oil – paraffin

Cover the test strips using the lid provided and label the setup with name (unknown sample), date, time, temperature and name of the assessor.
IV. The oxidase can be performed on the available kit or separately. The excess bacterial suspension is inoculated into a an agar plate and check for oxidase test
(BioMérieux, 2017)

• Incubation of strips in the chamber
I. Pour 5 ml water to the bottom of the incubation tray and place the strips on the incubation tray
II. Incubate the strips for 370c for 18-24 hours

• Reading the strips
I. After the incubation add proper reagents in the cupules
IND – 1 drop of Kovac’s reagent – the result read within few minutes
VP - I drop of Barrett’s reagent (A & B) - the result within 10 minutes
TDA – I drop of FeCl3 – result within few minutes
II. The result is read depending on the color change according to the chart below. If the color change is positive write it as +. Count the numbers within 3 set cupule.
III. Check for the seven digit number in the code book.
IV. If cupule of GLU tube is negative re-incubation is required further for 18-24 hours before addition of the reagent. (or less than 3 steps showing positive