FOOD MICROBIOLOGY SAMPLING GUIDE
TABLE OF CONTENTS
- Food Microbiology Overview
- Routine Testing Options
- Sampling Instructions
- EZ ReachTM Sponge Sampling Instructions
- PUR-BLUETM Swab Sampler Instructions
- Food Allergen Sampling Instructions
- Ambient and Compressed Air Sampling Instructions
- Water Sampling Instructions
- Sample Submission Checklist
- EMSL LABConnectTM
- EMSL Food Microbiology Lab Locations
Food Microbiology Overview
Industries Served
- Meat
- Seafood
- Dairy
- Nutraceutical Products
- Nuts and Almonds
- Baked Goods
- Beverages
- Grains and Cereals
- Canned and Frozen Foods
- Prepared Foods
- Snack Foods
- Dietary Products
- Food Supplements
- Private Label
- Antimicrobials
- Restaurants
- Hospitality and Retail
- Pet Foods
- Farm Animal Feed
- Food Packaging Material
Pathogen Testing
- Salmonella
- Listeria species
- Listeria monocytogenes
- E. coli 0157:H7
- Shiga Toxin-Producing E. coli (STEC)
- Campylobacter
Indicator Organism Testing
- APC (Aerobic Plate Count)
- Yeast/Mold
- Lactic Acid Bacteria
- E. coli
- Enterobacteriaceae
- Staphylococcus aureus
Routine Testing Options
Routine Quantitative Tests
| Analyte | Petrifilm | Pour Plate |
|---|---|---|
| Aerobic Plate Count | F102 | F151 |
| Yeast and Mold | F103 | F166 |
| Total Coliform/E. coli | F104 | F157 |
| Staphylococcus aureus | F105 | F183 |
| Standard Panel (includes above) | F101 | F180 |
Routine Qualitative Tests
| Analyte | Vidas | BAX (PCR) |
|---|---|---|
| Salmonella | F106 (env) F239 (25g) F139 (375g) | F192 (env) F190 (25g) F191 (375g) |
| Listeria | F107 (env) F236 (25g) | F193 (env) F187 (25g) |
| E. Coli O157:H7 | F108 (env) F233 (25g) F129 (375g) | F189 (env) F194 (25g) F195 (375g) |
Vidas vs. BAX
- VIDAS is based on enzyme linked fluorescent Assay (ELFA) technology, has short processing times and extensive matrix validations
- BAX is a PCR based assay
Bacterial and Fungal Identification performed by MALDI-TOF MS (VITEK-MS) or by DNA Sequencing
Shelf-Life Studies
Challenge Studies
FDA Detain
Sampling Instructions
Food
- Minimum 50 grams per pathogen requested
- Minimum 50 grams for all quantitative tests
- Sample into a sterile leak-proof container, ensuring a representative sample
Sponge (For Swabbing Environmental Surfaces)
- One sponge per pathogen
- One sponge for all quantitative tests
- Typically done on a 4”x 4” or 5”x 5” area
Sponge vs. Swab
There are two types of samplers that may be used for environmental sampling, a sponge and a swab. A sponge sampler can sample a larger surface area than a swab can. It can also support more pressure so you are able to scrub the area and breakup any biofilm that may be present. Swabs are much smaller than a sponge so they are able to fit into tight spaces, cracks, and in between pieces of equipment.
If you are sampling a large flat surface a sponge is the proper sampling tool. For nooks and crannies of machinery and other hard to reach areas a swab would be the proper sampling tool.
EZ REACHTM Sponge Sampling Instructions
- Label the sample bag with a permanent marker.
Note: If sampling for the presence/absence testing of pathogens, a single sponge is required for each specific pathogen test. Multiple quantitative indicator tests (e.g., Aerobic plate count, Coliform/E.coli, Yeast/Mold) can be performed from a single sponge. - Open the bag by tearing off the top of the plastic strip and using the white pull tabs.
- Keeping hands outside the bag, push the sponge handle out of the bag. Grasp the handle and remove the sponge from the bag. Be careful not to touch inside of the bag.
- Press the sponge portion of the device with firm pressure to ensure full contact with the desired sampling surface. Move the sponge back and forth in vertical direction while applying firm pressure. Flip the sponge and move the sponge back and forth in horizontal direction across the same surface area while applying firm pressure.
- After sampling is complete, insert the sponge portion only into the prelabeled sample bag.
- With your hands outside the bag, pinch the sponge while turning the handle in a counter-clockwise direction.
- Drop the separated sponge into the bottom of the bag and discard the handle. Roll down the top of the bag several times and fold over the wire tie to securely close.
- Collect all sponge samples in an insulated cooler with ice packs and ship overnight to EMSL Analytical, Inc. Sponge samples should not come in direct contact with the ice packs and should ideally be kept at 0-8o C (not frozen)* during transportation.
Additional reminders:
- Ensure that appropriate Personal Protective Equipment (PPE) is used and Good Manufacturing Practices (GMPs) are strictly adhered to during sampling activities.
- Ensure that the sponge samples do not come in direct contact with finished product to avoid potential for cross-contamination. The use of a secondary barrier container is recommended.
- During sampling activity, be mindful of the sequence of sampling activity as moving sponge samples from the raw food area into the finished product handling area can increase potential for cross-contamination.
- If sampling for quantitative tests (e.g., Aerobic Plate Count, Yeast/Mold, Coliform/E.coli) using Petrifilm methods, ensure that the sponges are hydrated with HiCap Neutralizing broth or letheen broth. Neutralizing buffer and D/E neutralizing broth contain chemical compounds that can interfere with Petrifilm methods.
- Verify that a completed chain of custody form (COC) is included in the container and that the sample descriptions exactly match the labels written on the samples.
Sampling Sponge
#8708925 (single)
#8708941 (dual)
*The temperature of the sponge or swab during transit is important to maintaining the viability of the target organisms. If the sponge or swab arrives to the lab too cold the organisms may die off in which case a false negative result could be returned. If the sponge arrives at the laboratory too warm there may be an overgrowth of bacteria and these could be in direct competition with the organism of interest thus causing a false negative.
** This sampling media cannot be used for Food Allergens. Please contact EMSL to order media for Food Allergen sampling.
PUR-BLUETM Swab Sampler Instructions
- Label the sample tube with a permanent marker.
Note: If sampling for the presence/absence testing of pathogens, a single swab is required for each specific pathogen test. Multiple quantitative indicator tests (e.g., Aerobic plate count, Coliform/E.coli, Yeast/Mold) can be performed from a single swab. - Unscrew the cap from the tube and remove excess media by pressing the swab tip against the inside of the tube.
- Remove the swab from the tube carefully.
- Press the tip portion of the device with firm pressure to ensure full contact with the desired sampling surface. Move the swab back and forth in vertical direction while applying firm pressure and rotating the swab to ensure entire swab tip makes contact with the surface. Change the direction 90o and move the swab back and forth in horizontal direction, repeating the same sampling process.
- After sampling is complete, insert the swab into the prelabeled tube and tighten the cap.
- Collect all samples in an insulated cooler with ice packs and ship overnight to EMSL Analytical, Inc. Samples should not come in direct contact with the ice packs and should ideally be kept at 0-8o C (not frozen)* during transportation.
Additional reminders:
- Ensure that appropriate Personal Protective Equipment (PPE) is used and Good Manufacturing Practices (GMPs) are strictly adhered to during sampling activities.
- Ensure that the swab samples do not come in direct contact with finished product to avoid potential for cross-contamination. The use of a secondary barrier container is recommended.
- During sampling activity, be mindful of the sequence of sampling activity as moving swab samples from the raw food area into the finished product handling area can increase potential for cross-contamination.
- If sampling for quantitative tests (e.g., Aerobic Plate Count, Yeast/Mold, Coliform/E.coli) using Petrifilm methods, ensure that the swabs are hydrated with HiCap Neutralizing broth or letheen broth. Neutralizing buffer and D/E neutralizing broth contain chemical compounds that can interfere with Petrifilm methods.
- Verify that a completed chain of custody form (COC) is included in the container and that the sample descriptions exactly match the labels written on the samples.
Pur-Blue Swab Sampler
#8708942 (1ml swab)
#8708928 (10ml swab)
*The temperature of the sponge or swab during transit is important to maintaining the viability of the target organisms. If the sponge or swab arrives to the lab too cold the organisms may die off in which case a false negative result could be returned. If the sponge arrives at the laboratory too warm there may be an overgrowth of bacteria and these could be in direct competition with the organism of interest thus causing a false negative.
** This sampling media cannot be used for Food Allergens. Please contact EMSL to order media for Food Allergen sampling.
Food Allergens Sampling
Avaliable Tests
| F724 | Fish Allergen | F029 | Crustacea Allergen |
| F020 | Peanut Allergen | F030 | Soy Allergen |
| F027 | Histamine | F034 | Lupine Allergen (Subcontract) |
| F021 | Almond Allergen | F035 | Mustard Allergen (Subcontract) |
| F022 | Egg Allergen | F036 | Sesame Allergen |
| F023 | Hazelnut Allergen | F037 | Casein Allergen (Subcontract) |
| F024 | Total Milk Allergen | F039 | Brazil Nut Allergen |
| F026 | Gluten Allergen | F040 | Cashew Allergen (Subcontract) |
| F028 | Walnut Allergen | F041 | Pistachio Allergen (Subcontract) |
| F006 | Food Allergen - speciality | F243 | Cashew/Pistachio |
*Other Allergens available upon request
Detection Limits
Quanitative Detection available for physical samples only. Tree Nuts (*), Sesame, and Swab Samples all
reported Qualitative Only.
| Test Name | Detection Limits |
|---|---|
| Fish | 4 ppm (200 ng/Swab) |
| Crusacea | 20 ppb (10 ug/Swab) |
| Histamine | 2.5 ppm |
| Egg | 1 ppm (2 ug/Swab) |
| Total Milk | 0.4 ppm (1 ug/Swab) |
| Gluten | 5 ppm (4 ug/Swab) |
| Soy | 40 ppb (2 ug/Swab) |
| Lupine | 2 ppm |
| Mustard | 2 ppm |
| Sesame | 5 ppm (5 ug/Swab) |
| Casein | 0.2 ppm |
| Peanut | 1 ppm (1 ug/Swab) |
| Cashew | 2 ppm |
| Pistachio | 1 ppm |
| Brazil Nut* | 5 ppm (5 ug/Swab) |
| Almond* | 2 ppm (2 ug/Swab) |
| Walnut* | 10 ppm (10 ug/Swab) |
| Hazelnut* | 5 ppm (5 ug/Swab) |
| Cashew/Pistachio* | 2 ppm (2 ug/Swab) |
* Detection limits may be subject to change depending on the kit used.
Sampling Instructions for Finished Product Food Sample
Minimum 5 grams per test. Place sample of food in plastic bag or the finished product in its own packaging. If the physical sample should be chilled or on ice, please ship in accordance.
Sampling Instructions for Swab
EMSL Product Code: 87M0017 – $2.00 Each Swab
**Clients will need to submit 1 swab per Allergen to be tested. We cannot sample multiple allergens on a single swab.
Sampling Swabs will be shipped to client on ice, and will need to be shipped back to Cinnaminson, NJ in a cooler, on ice. Samples must be analyzed within 72 hours of collecting this sample. Please ship back same day of collecting the sample(s).
DO NOT SWAB ON FRIDAY, SATURDAY OR SUNDAY. Due to the Hold Time, please swab the product and ship overnight to the lab Monday–Thursday
For Dry Surfaces: Remove swab from plastic holder and moisten using provided buffer solution. Swab across a target area of 5×5 cm in a cross-hatch pattern applying pressure so that the swab stick bends slightly (below). Rotate the tip while swabbing back and forth. Break off the end of the swab into a 3-inch tube provided. Using the transfer pipette provided, add no more than 2-3 drops of the buffer. Make sure to close the tube tightly to prevent leakage. Remember to label each sample clearly.
For Wet Surfaces: Remove swab from plastic holder. DO NOT moisten before swabbing. Swab across a target area of 5×5 cm in a cross-hatch pattern applying pressure so that the swab stick bends slightly. Rotate the tip while swabbing back and forth. Break off the end of the swab into a 3-inch tube provided. Using the transfer pipette provided, add no more than 2-3 drops of the buffer. Make sure to close the tube tightly to prevent leakage. Remember to label each sample clearly.
Shipping Instructions
All swabs should be shipped overnight to the lab under 39-46˚F (4-8˚C) conditions (return in a cooler on ice). Physical samples can be shipped as-is. Ship all samples directly to our Corporate Headquarters: EMSL Analytical, Inc., 200 Route 130 N, Cinnaminson, NJ 08077
Ambient And Compressed Air Sampling
Air quality monitoring within a food processing facility is a crucial component of maintaining a comprehensive environmental monitoring program. Without proper engineering for directing the flow of air and active monitoring of the air within the processing areas, bioaerosols may become a source of product contamination that compromises the safety and quality of foods produced. As such, commonly adopted food safety and quality management programs (e.g., BRC, SQF) prescribe the need for managing and monitoring the microbiological quality of the air to control the risk of product contamination from bioaerosols. In addition to direct contamination of the product, the bioaerosols may land on processing surfaces or equipment and when the right conditions exist (e.g., moisture, organic matter), the physical surfaces harboring microbial contaminants have the potential to be a vector of cross-contamination. Compressed air can also come in direct contact with food products. For example, it can be utilized for adding air into packages to protect food products such as a bag of chips or for cleaning debris off large surfaces that come in contact with the products. Since compressed air can harbor microorganisms and contribute to the contamination of the finished products, it is important that all types of air systems with potential product safety and spoilage implications are continually monitored.
When testing for the microbiological quality of ambient and compressed air, the methods outlined below are air testing strategies that are commonly used:
- Sedimentation (settling) method for ambient air monitoring
- Standard agar plates utilized for growth of bacteria and fungi (yeast and mold) are directly exposed to the areas of interest for a user-specified length of time (generally 15 minutes). Airborne particles are deposited onto the surface of agar plates by the force of gravity. The plates are incubated in accordance with the applicable methods and bacterial or fungal colonies counts are obtained. While the sedimentation method offers a relatively simple and inexpensive means to collect ambient air samples, this method of air sampling selects for heavier particles that settle rapidly as the method relies on the gravitational force for sample collection.
- Supplies and EMSL Test Codes
Test Test Code Agar Plate Agar Plate Product ID Aerobic Plate Count F163 Tryptic Soy Agar (TSA) 8714001 Yeast and Mold F164 Malt Extract Agar (MEA) 8714003
- Impaction method for ambient air monitoring and compressed air testing
- The impaction method involves actively drawing a specified volume of air via a mechanical vacuum. Particles suspended in the air are pulled in through a perforated metal plate and impacted onto the surface of agar plates and subsequently incubated to observe bacterial or fungal growth. This method has the advantage of allowing users to standardize the amount of air collected, thus enabling normalization of the data over sampling events. On the other hand, the method requires the rental or purchasing of the equipment as well as careful handling and training to avoid contamination of the apparatus prior to sampling.
- Supplies and EMSL Test Codes
Test Test Code Agar Plate Agar Plate Product ID Aerobic Plate Count F163 Tryptic Soy Agar (TSA) 8714001 Yeast and Mold F164 Malt Extract Agar (MEA) 8714003 - Impactor Samplers
Air Testing Type Sampler Description Product ID Rental Pricing (Daily) Ambient EMSL VP-400 Impactor Kit
SAS Air Sampler87RD007
87RD021$50 USD
$125 USDCompressed SAS Pinocchio Super II Sampler 87R5034 $175 USD
Total Coliform Water Sampling Guide
Chain of Custody
Must contain sampling date, time sampled, and sample source. This is needed to determine whether samples are within hold times and valid for analysis. If looking for Total coliforms, please inform us if you would like Presence/ Absence (Colilert) (EMSL Test Code M017) or Enumeration (MPN-Most Probable Number or MFT-Membrane filtration technique) (EMSL Test Code M114).
Sample Collection
All water samples must be taken in approved, sterile sampling containers, which our laboratory can provide upon request. Treated (municipality/distribution systems) water samples must be de-chlorinated with sodium thiosulfate (this is already in bottles that are provided by our laboratory). Keep sampling bottle closed until it is to be filled at the sampling location.
Distribution or sink tap sample
- Remove aerator from faucet.
- Rinse faucet with a bleach solution.
- Flush line- by turning tap fully on and letting it run for two to three minutes, or for a time sufficient to permit clearing the service line.
- Reduce water flow to permit filling bottle without splashing. 5. 100 mL is needed for each sample submitted for analysis.
Hold Times
Hold times for regulatory samples are 30 hours for the Presence/Absence test method and 30 hours for membrane filtration method.
If client is aware that hold times are going to be exceeded but would like analysis to proceed anyway, please indicate this on the Chain of Custody.
If hold times are exceeded results are invalid and this will be noted on the final report.
Turn Around Times
Total coliform-Presence/Absence (Colilert) or enumeration (MPN) results can be reported in 24 hours.
Sample Shipping
All samples must be shipped cold, not frozen and should remain up right. The best way to ship method of shipment for these samples is to use ice packs, not soda bottles filled with frozen water, bags of ice or just loose ice. Samples that are not shipped properly could end up getting contaminated or rejected.
In order to meet the recommended 30 hour hold time, it is best to sample after 12 pm so the overnighted package will arrive to EMSL within that hold time.
Sample Submission Checklist
Submit Sufficient Quantity of Samples
- Quantitative tests (reported as CFU/g or CFU/mL)
- Minimum 50 grams food or a single sponge/swab for all tests
- Examples: Aerobic Plate Count, Yeast/Mold, Coliform/E. coli
- Qualitative tests (reported as present or absent)
- Minimum 50 grams food or a single sponge/swab for each pathogen test.
- Examples: Listeria, Salmonella, E. coli O157:H7
Fill Out a Chain of Custody (COC)
- Labels on samples match the sample ID/ description on COC
- Select Turnaround Time. All TATs are end of business day. (Food Micro TATs are due upon completion.)
- Tests codes are indicated on COC for ALL samples.
- Special instructions are added, if applicable (e.g., specifications, additional dilutions, composite sampling)
Properly Package Samples
- Prepare a clean insulated box
- Line the bottom with frozen cold packs (2 minimum)
- Place a layer of insulating material (e.g., bubble wrap) on top of the ice packs
- Insert samples in a sealable bag, seal tight, and place them in the box
- Place another layer of insulating material on top of the ice packs
- Line the top with another layer of frozen cold packs (2 minimum)
- Include a completed Chain of Custody form. Place the COC inside a plastic bag or keep isolated to prevent the document from getting wet from the ice packs
- Seal the container
- Apply shipping label and send out for overnight delivery
Notes
- Keep environmental and finished product samples segregated (e.g., in separate sealable bags) to prevent cross-contamination.
- Ambient samples do not require ice packs; however, exposure to extreme temperatures should be avoided.
- Do not freeze refrigerated products.
Step 1
Prepare a clean insulated box
Step 2
Line the bottom with
frozen cold packs
Step 3
Place a layer of insulating material
(e.g., bubble wrap)
Step 4
Place samples
Step 5
Place another layer of insulating material (e.g.,bubble wrap)
Step 6
Line the top with another
layer of frozen ice packs
Step 7
Include a completed
Chain of Custody Form
Step 8
Seal the container
Step 9
Apply shipping label and send out for overnight delivery to EMSL
Order your shipping container
EMSL Product
# 8799404
Shipping Cooler
6 x 6 x 6
EMSL Product
# 8799401
Shipping Cooler
8 x 8 x 8
EMSL Product
# 8799402
Shipping Cooler
12 x 10 x 9
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EMSL Food Microbiology Lab Locations
New Jersey – Cinnaminson (Corporate)
200 Route 130 North, Cinnaminson, NJ 08077
(800) 220-3675, c@emsl.com
Florida – Orlando
3303 Parkway Center Court, Orlando, FL 32808
(407) 599-5887, orlandolab@emsl.com
Florida – Tampa
5406 Hoover Blvd, Ste 21, Tampa, FL 33634
(813) 280-8752, tampalab@emsl.com
Indiana – Indianapolis
6340 CastlePlace Dr., Indianapolis, IN 46250
(317) 803-2997, indianapolislab@emsl.com
Missouri – St. Louis
100 Green Park Industrial Court, St. Louis, MO 63123
(314) 577-0150, saintlouislab@emsl.com
North Carolina – Raleigh
2500 Gateway Centre Boulevard, Suite 600, Morrisville, NC 27560
(919) 465-3900, raleighlab@emsl.com
Texas – Houston
5950 Fairbanks North Houston Rd, Houston, TX 77040
(866) 318-3920, houstonlab@emsl.com
For additional information on laboratory services, laboratory locations, sample submittal, and much more, visit www.foodtestinglab.com or call
Northeast: (800) 220-3675
Southeast: (888) 958-8170
West and Midwest: (877) 435-5227
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