Premi®Test sample pre-treatment procedure for kidney

Background

In a soft tissue like kidney, the sampling procedure can easily result in extensive tissue damage and the consequent release of intra-cellular contents such as natural lysozyme like inhibiting substances. To prevent these inhibitors interfering with the test result a special protocol is required to use the Premi®Test for the detection of antibiotic residues in kidney.
Therefore DSM has developed a proprietary technology. This patented technology is described in this technical bulletin. Inactivating the proteinaceous factors through a short heat pre-treatment of the kidney juice can easily prevent the influence of naturally occurring inhibiting substances.

1. Sample preparation method

1. Wash hands before use and make sure to use a clean working surface.
2. Cut the kidney horizontally.
3. Cut out of the kidney medulla a piece of around 1-2 cm³.
4. Squeeze the kidney sample with a meat- press (supplied with the Starterkit Premi®Test).
5. Collect the fluid sample in a clean container.

2. Instructions for using Premi®Test

1. Remove the aluminum foil carefully from the ampoule(s).
2. Use a clean tip on the syringe.
3. Transfer 100 µl of juice onto the agar in the ampoule, by pressing the syringe once and releasing it. It will automatically take up the required volume.
4. Close the ampoules with the plastic foil supplied with the kit.
5. Place the ampoule(s) in the Premi®Test 2-Step Incubator and push the “program” button, as described in the instructions of this Incubator.
6. The Premi®Test 2-Step Incubator automatically heats the samples for 10 minutes at 80°C.
7. After this heat pre-treatment, the Premi®Test 2-Step Incubator incubates the samples at the required temperature of 64°C (± 0,5 °C).
   Click here  for more informations
8. Incubate the sample until the negative control (kidney what has been tested previously negative) changes color.

3. Reading the test results

1. When the negative control changes color from purple to yellow (approx. 3 hours), the results can be red.
2. Read the results from the bottom 2/3 part of the ampoule.
3. A clear color change purple to yellow indicates that the antimicrobial compounds are below the Premi®Test detection limits.
4. A purple color  indicates the presence of antibacterial substances at or above the detection limits of the Premi®Test.