Laboratory testing for allergen and microbiology is a process that uses different techniques to identify specific allergens and bacteria. 


One challenge for food processors in a plant is changing from processing one product that contains an allergen to a similar product that does not contain the allergen, but they are produced on the same piece of equipment. The U.S. Food and Drug Administration (FDA) states that precautionary labeling cannot be used to substitute for Good Manufacturing Practices (GMPs). This implies that companies should thoroughly clean between products to prevent carry-over.

Microbiology Testing

Daily Laboratories offers a wide range of microbiological services for the food and water industries. These can be required testing for regulatory purposes to routine testing for monitoring for your HAACP plan. We can test for pathogens as well as sterility. We can also assist with shelf-life studies and product returns.


Our microbial analyses are performed using culture, biochemical and immunological methods. Because the analysis is normally based on a small sample taken from a larger volume or area, all methods rely on statistical principles.


All of our analyses are by AOAC-certified methods.

Aerobic Plate Count (APC) – Standard Plate Count (SPC) – Total Bacterial Count
All of these mean the same thing. This test is an enumeration of the total aerobic bacterial count of a sample. The results are reported as CFU’s (colony forming unit) and can be a useful test to validate cleaning and sanitation methods. It can be used as part of the acceptance criteria for products as well as gauge the freshness.

This test normally takes 48 hrs.

Total coliforms and E. coli

Coliforms are referred to as “indicator organisms”. They are not pathogenic by themselves, but their presence indicates that the conditions are favorable for pathogens to be present. Generic E. coli is a coliform, but is fecal in origin. Total coliform and E. coli test is a way to assess the cleanliness of the area or the food. It can also show the potential for additional contamination.

Residual bacterial count and residual coliform count (RBC & RCC)

These tests are used for single-service containers and closures as outlined in the Pasteurized Milk Ordinance Appendix J: Standards for the Fabrication of Single-Service Containers and Closures for Milk and Milk Products.  Daily Laboratories is an approved laboratory for the examination required under these standards.

Yeast & Mold

This test enumerates the total yeast and mold count in a sample. No identifications are made.

Yeasts and molds can cause deterioration and decomposition of foods. They can grow in  grains, nuts, spices and herbs and other foods in the fields and during storage. They can also grow in processed foods.  Yeasts and molds can affect the flavors and odors of foods. Some molds can produce toxins.

This enumeration can take 3-5 days.


Enterobacteriaceae comprises several genera of bacteria. This group of bacteria has been used in Europe for many years as indicator organisms for food quality instead of coliforms. Many companies in the US have adopted this practice.

Listeria sp.  

Listeria sp. is a bacteria that is naturally found in the environment.  A small dose of Listeria can be dangerous to the high-risk populations (immunosuppressed, very young, very old and pregnant).

Listeria sp. has been associated with raw milk, raw soft cheeses, raw vegetables, some fermented raw-meat sausages, uncooked hot dogs and raw meats. It can survive and grow on damp surfaces at refrigerated temperatures.  Products and environmental surface samples can be tested for the presence or absence of Listeria.

Salmonella sp. 

Salmonella sp. can be found in many animals, particularly swine and fowl. It will infect anyone, but the high-risk populations are most severely affected.

Many foods have been associated with Salmonella outbreaks; raw poultry and meats, eggs, raw milk, sauces, spice mixes, cream-filled desserts and peanut butter to name a few. Products, components and environmental swabs can all be tested for the presence of Salmonella sp. 

Staphylococcus aureus 

Staph. aureus is also known as coagulase-positive Staph.  Staphylococcus sp. occurs naturally in the environment, but humans are the primary source. Food handlers are frequently the source of contamination with S. aureus, but equipment and surfaces can also be a source.

Some foods that have been associated with staphylococcus food poisoning outbreaks include creams and fillings, mixed salads such as macaroni, chicken and potato, and egg products. Foods that require a lot of processing during preparation and are not kept hot or cold enough are commonly involved. The illness is caused by ingesting the enterotoxins produced by the bacteria.

Products and environmental swabs can be tested for the presence of Staphylococcus aureus. 

E. coli 0157:H7 

E. coli 0157:H7 is a very pathogenic strain of E. coli. It can cause serious medical issues.  In many outbreaks, undercooked ground beef has been the source. Other sources have included raw milk, unpasteurized apple juice/cider, salami and raw vegetables.

Raw ground meat and trim samples, as well as produce and environmental swabs, can be tested for the presence of E. coli 0157:H7.   

Campylobacter sp. 

Campylobacter sp. is found in the intestinal tracts of many healthy animals, including fowl and cattle.  It has been isolated from non-chlorinated water sources such as creeks and ponds, as well as from flies. It causes human illness and diarrhea.

Campylobacter frequently contaminates raw chicken and has been found in raw milk.  Raw and processed products and environmental samples can be analyzed.

Suitability test –
Laboratory pure water quality test – Growth ratio

This test is required at least annually by the EPA and state health departments for water laboratories as part of the intralaboratory quality control practices. The test is complex, requires skill and experience, and is not easily done on an infrequent basis. It requires work over 4 days, an independent ultrapure water, high purity reagents, and aseptic technique. The test is very sensitive to toxic agents or growth-promoting substances.

Water Activity Test

Water activity (aw) is the ratio of the vapor pressure of the water in the sample to vapor pressure of pure water at the same temperature. This method is a measurement relating to the free, unbound water present in food and food products. Water activity has little, if any, relationship to the total moisture content of the food.

Water activity does provide a means of assessing the storability and bacterial susceptibility of shelf-stable foods.  It is know that microorganisms cannot survive below certain aw levels, depending on the type of microorganism. This test can be performed on nearly all foods, spices and pharmaceuticals.