Sample should be placed in a well-sealed container: such as a
whirl-pak, zip-lock, or plastic container with a lid. Liquids can
be sent in their original commercial packaging (with tight-fitting
lid) or in plastic bottle. Perishables should be accompanied by an
ice-pak (not ice in a bag).
How much of a
sample should I send?
A
minimum of 100 grams of product is required when sending in a sample
for testing. We retain a portion of the sample for three months before being
properly destroyed. –This does not apply to swab samples. If you do
not have 100 grams, we can manage with 20 grams in most cases.
What if I
want my sample returned to me?
If you want your sample returned, you must state so on the
Request for Sample Form. You will be charged for shipping.
PAYMENT INFORMATION
Payments are
normally made by credit card or wire transfer. We accept checks
however your products will be shipped after the check has cleared.
Net-30 accounts can be established by contacting the administration
department, and requires credit references.
EZ Gluten®
TEST KIT
What if my sample absorbs all of the extraction solution?
If a
sample absorbs all of the extraction solution, and there is no clear
liquid layer on top of the sample, try letting the sample settle for
an extra 5 minutes (10 minutes total). If this does not result
in enough clear solution to perform the test, then it may be
necessary to repeat the test with a new vial of extraction solution,
this time using only half a spoonful of the sample. Using less
sample will effect the sensitivity of the test, but may be necessary
for highly absorbent samples.
What is the Hook line?
A high
dose "hook effect" refers to the false negative result seen with
lateral flow tests when very high levels of target are present in
the tested sample. Under these conditions, unbound gluten can block
the test line, interfering with binding of the colloidal
gold-labeled antibody-bound antigen, resulting in a false negative
result. The Hook line found on the EZ Gluten® test strip
allows the user to determine if a weak or absent signal at the Test
line is due to low levels of gluten, or to excessively high levels
of gluten. If the Test line is weak or negative, and the Hook line
is present, then the weak or negative signal is due to low levels of
gluten.
- If the Test line is weak or negative, and the Hook line is not
present, this indicates a hook effect, or a high level of gluten
in the sample. The EZ Gluten® test can detect gluten levels
as high as 100,000 ppm (10%).
SPECIATION TEST KITS
How sensitive are the kits?
You can find specifics listed on the kit data sheets.
These assays are
intended for use as a qualitative test to estimate the meat species
content. The color development is proportional to the original
amount of specific antigen in the extract, but one should not
attempt to quantify the amount of species tissue in a sample based
on this assay. Variations in the sample content (e.g. % lean
tissue, % moisture, % fat, etc.) and variations in sample treatment
(e.g. cooking times, temperatures, etc.) of samples will affect the
amount of detectable antigen in the extract. Therefore, the level
of the antigen present and the intensity of the color reaction are
related to the sample composition, processing, and other factors.
Can I use an ELISA-TEK™ Cooked or Raw Meat Speciation Kit to
detect the presence of chicken egg proteins in my product?
If your product is uncooked:
The Raw Meat Poultry ELISA kit will react strongly in the presence
of raw whole egg, egg yolk and egg white with yolk contamination.
These materials, when extracted as per the kit instructions, product
signals, which are similar to a 100% chicken tissue positive
control. Raw egg white alone will give a signal greater than a 1.0%
chicken tissue positive control.
If your product is cooked:
Cooked whole egg, egg white, egg yolk and yolk-contaminated egg
white all give detectable signals in the Cooked Meat Poultry ELISA
at levels below a 1.0% cooked chicken tissue control when extracted
as per the kit instructions therefore, processed dried egg white
additive should produce similar results.
How long does testing take and how many samples can be tested?
Excluding sample preparation times, the Raw
Meat Speciation and the Cooked Meat Speciation tests take
approximately 60 minutes and 3 hours, respectively. Both kits can
be used as a 96-well unit or may be divided into a variety of strip
formats depending on the number of samples to be analyzed and the
number of replicates desired. USDA-FSIS protocols require use of
quadruplicate microwells for each control and sample extract,
through for screening purposes duplicate microwells for each control
and sample extract may be adequate.
What is the difference between the raw and cooked kits?
The ELISA-TEK™ Raw Meat Speciation Kits use
antibodies raised to species-specific serum albumin, whereas the
ELISA-TEK™ Cooked Meat Speciation Kits utilize antibodies raised to
heat-resistant glycoproteins found in muscle and other blood-fed
tissues.
How are results determined? Do I need special equipment?
The completed assay may be assessed
visually or with the aid of a microplate reader or spectrophometer.
Visual assessment of the presence or absence of green coloration can
be aided through the use of appropriate positive controls
representing suitable ‘cut-off’ levels (i.e., 1% tissue).
Microplate readers should be able to read
absorbances at 414 nm (405-420nm acceptable). Test samples are
classified positive or negative based on the relation of their mean
absorbances to the absorbance of a 1% positive tissue control. If
following USDA-FSIS protocols using a dual wavelength reader, read
the absorbance at 414nm with a 492nm reference filter (485-500nm
acceptable). Specific USDA assay validity parameters are provided
in the kit instruction.
What are the potential causes of erroneous results?
Poor reproducibility of replicate samples
or significant color in the Negative Control wells (high
non-specific binding [NSB] values) are often the results of
insufficient washing or can be attributed to contamination of the
ABTS substrate or splashing of the Avidin Peroxidase.
Cross contamination of tissue extracts can
also lead to false positive results. This can be controlled during
the sample preparation stages by using disposable materials, and
thoroughly cleaning equipment between stages to remove all traces of
possible contamination. Wherever possible all reusable equipment
should be very easy to decontaminate, since both serum
albumin and cooked protein antigen can be very difficult to clean
from surfaces.
What is the difference between the raw albumin control and the lean
tissue control in the Raw Meat Speciation Kits? Which should be
used?
The raw albumin controls can be used as true positive and negative
controls in a raw test but are NOT equivalent to 100% tissue
positive controls and should NOT be used for preparation of 1%
tissue positive controls. Note that care should be taken not to
cross contaminate meats used for preparation of tissue controls.
Tissue control extracts are more representative of ‘real world’
samples (e.g. a complex tissue matrix that is similar to a sample
meat extract) than pure albumin control. Additionally, the raw
albumin controls are formulated to represent a 5-10% tissue control,
and we recommend for regulatory protocols that a 100% tissue control
be used.
