This proficiency testing program is intended to provide a measure of consistency and accuracy among laboratories and their technicians. This program may be subject to revision as data are accumulated.

Quality Certification Services Inc. will publish a list of qualified laboratories that pass both qualitative and quantitative guidelines. This list will include laboratory name, technician name, and assays for which the laboratory demonstrated proficiency. Laboratories may elect to report results less frequently to internally assess their performance, but will not be listed as certified until monthly reporting of analysis is complete.

Who can participate in the QCS ELISA Proficiency Program?

This program is open to any laboratory analyzing milk samples using ELISA. Participation in this program is voluntary and is not limited by: test kit manufacturer, geographic location, or size. Participating laboratories do not need to be affiliated with a DHI organization or any other government entity.

Participation in other certification programs offered by Quality Certification Services Inc. or other entities is not required to join the ELISA Proficiency Program.

Why develop a proficiency program beyond that offered by the USDA?

While the USDA annual proficiency program is considered the primary program for laboratory accreditation, especially for National and State Voluntary Control Programs, many in DHI feel that the annual frequency of this program is not sufficient.

The QCS ELISA Proficiency Program is being developed to:

• provide a high assurance of accuracy to dairy producers who use results for management decisions including treatment and culling.
• potentially satisfy the QC requirements of DHI and industry partners who rely on data for genetic and management research.
• either substitute or suffice for the accreditation provided by USDA as this program surpasses the current annual program.

Why evaluate laboratory technician performance in the proficiency program?

The variability associated with laboratory technician running ELISA is expected to be larger than the laboratory technician variation associated with traditional component analysis of milk. Since other programs do evaluate technician performance, a current estimate of variability is not available. The data gathered through this proficiency program will be used to assess the magnitude and significance of this variation.

What are the costs for the QCS proficiency program?

The costs are divided into two categories.

• The first category is for administration, data collection and analysis. The annual cost for this category is $360 per laboratory, which includes one technician, and $120 for each additional technician. These fees are billed by Quality Certification Services Inc. on an annual basis. Laboratories entering the program during the calendar year will be billed on a prorated basis.
• The second category is the cost for the monthly 'Samples Unknown.' The annual cost for this category is $420 and is paid directly to the Samples Unknown Supplier. Each set of 'Samples Unknown' will be able to accommodate up to three laboratory technicians. If required, individual sets of Samples Unknown will cost $35.

Do all technicians have to be enrolled in the proficiency program?

The current proficiency program is voluntary in all aspects. Most laboratories have a primary ELISA technician who will be backed up by additional technician(s) on certain occasions. Laboratories are encouraged to have all technicians performing ELISA enrolled in the program. It is however, the responsibility of the laboratory manager to ensure the daily accuracy and consistency of ELISA testing. The monthly 'Samples Unknown' should provide enough milk for up to three laboratory technicians.

How should the monthly 'Samples Unknown' be analyzed?

The 'Samples Unknown' should be tested according the standard procedures used by the laboratory for commercial samples. As a general rule, treat the 'Samples Unknown' as commercial samples and report the raw data that would have been used for calculating the ELISA scores and interpretation reported to veterinarians and producers. The Samples Unknown contain 10 duplicate milk samples so there is no need to rerun 'positive' samples.

The unknown samples are are sent to the laboratories on the Monday of the third full week of each month. Laboratories have until the last business day of the each month to analyze and report the results to QCS. This protocol should allow adequate time for those laboratories with less frequent ELISA testing to incorporate the unknowns analysis into routine commercial sample analysis. Please refer to the current calendar for exact sample shipping dates and reporting deadlines.

A monthly proficiency programs seems excessive - why the need?

The current frequency was chosen to provide similar measures of accuracy and consistency as demonstrated for traditional milk component analysis in DHI. Dairy producers and allied industry partners have a high expectation of accuracy that may not be offered by an annual monitoring program. Moreover, the proficiency program will benefit from the large amount of data that will be accumulated to evaluate sources of variability.

The table above provides an estimate of the per sample costs of the program to certify two technicians for laboratories with various commercial testing volumes. The calculations assume $2.50 to run a single well for ELISA, 1.5 wells per unknown sample, and 4 standards. When run with commercial samples however, the actual costs associated with labor and standards would be diluted.