PYR DISC

K1538B - 50 TESTS $26.00

PRINCIPLE/DISCUSSION:

Enzymatic hydrolysis of L-pyroglutamic acid ß-naphthylamide (PYR) releases free-ß naphthylamine which is detected and shown by the color change after adding PEP reagent.

ACTIVE INGREDIENTS

The discs contain L-pyroglutamic acid ß-naphthylamide: naphthylamides have been identified as possible carcinogens however when used as directed the discs present no hazard. PEP reagent contains a small amount of hydrochloric acid , is poisonous, mildly corrosive, and stains clothing and hands. Handle with care. Consult poison control center if ingested.

MATERIAL REQUIRED:

The tests require fresh 24 hour growth on plated media not available from KEY. Consult a suitable manual for recommended media for the specimen. The following items are required but not provided:

Distilled water, pH 7.0-7.2

Slide or small test tube

INSTRUCTIONS:

(1) Place the disc onto a slide and moisten with a loopful of distilled water. Do not use excessive water. The disc should be only wet enough to hold it in place.

(2) Smear with a paste of the organism from a fresh pure 24 hour culture plate or slant using the sticks provided or a loop.

3) Wait 2-5 minutes (at room temperature) then add 1 drop of PEP reagent. Wait at least 1 but not more than 2 minutes for color to develop.

INTERPRETATION:

The appearance of a dark pink to red color is positive. Indole reactions of organisms grown on any media containing tryptophane (e.g. blood agar) may interfere but will still produce predictable reactions. From such media, positive PYR reactions will range from dark pink or red (PYR+/indol-) to purple (PYR+/indole+). Green or turquoise (indole+), and yellow (indol-) are both PYR negative *.

STORAGE:

Store discs and reagent tightly covered in the dark at 2-8C. Discs may be used cold.

QUALITY CONTROL:

Each lot should be tested with known positive and negative organisms. Some suggested strains are listed. Dispose of all used material in a manner appropriate for biohazardous material.

E. faecalis 29212 = POSITIVE

S. agalactiae 13813 = NEGATIVE

(*Positive PYR and Indole may be shown by testing with Citrobacter diversus and positive indole only can be shown with E. coli.)

REFERENCES

(1) Manual of Clinical Microbiology, Fifth Edition, Chapter 36, Enterobacteriaceae

(2) Manual of Clinical Microbiology, Fifth Edition, Chapter 29, Streptococcus.

            9811K