Check Mark Laboratory

Dairy Wet Chemistry Testing

Check Mark Laboratory is a division of Dairy One and one of the leading wet chemistry laboratories in the northeast. All laboratory testing is done using AOAC methods. The laboratory conducts chemistry testing for fat, total protein, true protein, total solids, casein, lactose, and direct microscopic somatic cell count.  Check Mark can analyze any liquid dairy product for these components; refer to page 2 of the submission form for details.  These may include but are not limited to: heavy cream, whey, retentate, yogurt, milk replacement products, reconstituted powders, or non-bovine milk.

Please include a completed copy of the Check Mark Sample Submission Form when submitting samples.

Weekly Calibration Samples

The Check Mark laboratory also manufactures raw bovine milk calibration standards each week to be used in other labs across the region. We can also develop customized calibration standards specifically for your IR analyzer to monitor your specific dairy product.

The component calibration samples (used to calibrate for fat, protein, etc) are shipped on Tuesdays via UPS and the results are made available by Thursday afternoon.  The somatic cell control samples are shipped on Wednesdays.  Shipping and handling is included in the prices, with Next Day shipping or Second Day shipping at an additional cost.  Customer pays the fee to return the shipping container.

Component calibration samples are manufactured each Monday and usually shipped out on Tuesday with results available Wednesday. The ranges that the samples typically encompass are as follows: 3.00 – 4.70% butterfat and 3.10 – 3.80% true protein. Somatic cell control samples are manufactured each Wednesday and shipped out on the same day with results available Thursday.  Please contact us with any questions; we are happy to accommodate special needs if we are able to.

For a price list or to inquire about Check Mark’s services, contact us at

Weekly Calibration Sample Results

Attention calibration sample customers! We have restructured our calibration sample program. Find out more about how you will be affected here. Effective the week of November 11, 2019.

Current Results:

11/13 1773 Green

11/14 1773 Green SCC

Previous Results:

11/6 1772 Blue *Note that this will be the final 1-12 standard calibration set manufactured. Please read more about our changes above and contact us with any questions.*

11/7 1772 Blue SCC

10/30 1771 Black

10/31 1771 Black SCC

10/23 1770 Green

10/24 1770 Green SCC

10/16 1769 Blue

10/17 1769 Blue SCC

10/9 1768 Black

10/10 1768 Black SCC

10/3 1767 Green

10/2 1767 Green SCC

9/25 1766 Blue

9/26 1766 Blue SCC