Rapid Quality Control Test Kits


  1. Take a small portion of sample with the micro-spatula and place it in one depression of the spot plate. (No more than enough to cover about 1/2 of the bottom of the hole).
  2. Wet the sample in the spot plate with 5 drops of Reagent B. Then add 1 drop of Reagent C. The sample should not absorb all the available liquid.
  3. Place the dark cardboard rectangle over the spot plate for 10 minutes to protect the PRO-CHEK reaction from direct sunlight.
  4. After 10 minutes, compare the sample portion to the color photograph in the box lid.

The amount of activity described on this table corresponds to the positions on the color photo:

NO ACTIVITY beans are overcooked INTENSE MED-HIGH
TRACE beans have browned TRACE beans have not browned LIGHT

Interpretation of results for ruminant animals:

60% UIP 55% UIP <50% UIP

A “Trace” of light blue color when the ground soybeans are just beginning to show light browning is the correct point for 60 + 5% Undegradable Intake Protein (UIP) or by-pass protein (bottom left photo). It is necessary to see both a trace of blue PRO-CHEK color plus browning of the soybean meal.

A “Trace” of light blue color without darkening the soybean meal is approximately 55 + 5% by-pass protein (bottom middle).

A small amount of blue color distributed around the sample (“Light”: bottom right) is not adequately cooked to optimize the amount of heat energy put into the roasted meal. It may have less than 40 or 50% by-pass protein.

“Intense” & “Med-High” have no value for by-pass protein.

“No Activity” is overcooked for optimum by-pass protein because Insoluble Intake Protein (IIP or heat- damaged protein) begins to be produced at this point. Overcooked products can still be used, but the amount of IIP cannot be estimated with this kit.

The sample must have no SOY-CHEK activity or the PRO-CHEK test is invalid for UIP/by-pass protein estimation, due to sample variation from inadequate cooking.

Interpretation of results for mono-gastric animals:


“Intense” is the correct PRO-CHEK reaction. “Intense” is essentially every particle showing some blue color activity. Refer to the color photo inside the box lid, and the corresponding table under “PRO-CHEK Instructions”.

When using SOY-CHEK and PRO-CHEK together to check for overcooking of soybeans for poultry and swine, the desired reactions are no urease activity (a 5 or 6 on the SOY-CHEK scale) and “Intense” PRO-CHEK activity (top middle).

“Light”, “Trace” and “No Activity” are all considered overcooked for mono-gastric animals.

Note: Some variation in different parts of a sample is expected. Take a second sample to compare variability within samples. A second sample and a control raw sample will assist in your interpretation. You can compare the reaction of the raw sample to the “Intense” blue reaction in the photo (top middle). This gives you a direct comparison to compare with the color photograph and to calibrate your eye to the photo.


Undegradable Intake Protein (UIP), commonly called by-pass protein, is estimated by several laboratory tests using various protein degrading enzymes. These tests have been correlated to animal digestibility tests. PRO-CHEK has been correlated to these major lab tests and to direct animal tests using roasted soybean meal and cottonseed meal. PRO-CHEK is not effective on extruded soybean products. PRO- CHEK tests involve no protein degrading enzymes. Thus protease inhibitors in cottonseed meal cannot invalidate PRO-CHEK by-pass tests.

Caution PRO-CHEK has not been tested enough yet to be sure that it will correlate to UIP when using animal protein sources such as blood meal, meat meal, etc.


PRO-CHEK complements SOY-CHEK testing and eliminates the need to maintain a trace of urease activity to prevent overcooking for monogastric animals. A trace of SOY-CHEK activity is still recommended when using SOY-CHEK alone to determine the degree of cooking for mono-gastric animals.

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