K-ASSAY 

KAMIYA BIOMEDICAL COMPANY

KAMIYA BIOMEDICAL COMPANY

Human Insulin Degrading
Enzyme (IDE) ELISA
For the quantitative determination of human IDE inserum, plasma, tissue homogenates, cell lysates, cell culture
supernates and other biological fluids

Cat. No. KT-18252

For Research Use Only. Not for use in diagnostic procedures.

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Product Information
Human Insulin Degrading Enzyme (IDE) ELISA
Cat. No. KT-18252

INTENDED USE
The kit is a sandwich enzyme immunoassay for the in vitro quantitative measurement of human IDE inserum, plasma, tissue homogenates, cell lysates, cell culture supernates and other biological fluids. For
research use only. Not for use in diagnostic procedures.

COMPONENTS
Reagents

Quantity

Pre-coated, ready to use 96-well strip plate1

Calibrator

2

Calibrator Diluent

1 × 20 mL

Detection Reagent A

1 × 120 µL

Detection Reagent B

1 × 120 µL

Assay Diluent A

1 × 12 mL

Assay Diluent B

1 × 12 mL

TMB Substrate

1 × 9 mL

Stop Solution

1 × 6 mL

Wash Buffer (30X concentrate)

1 × 20 mL

Plate sealer for 96 wells

4

MATERIALS REQUIRED BUT NOT SUPPLIED
1.
2.
3.
4.
5.
6.
7.

Microplate reader with 450 ± 10 nm filter.
Single or multi-channel pipettes with high precision and disposable tips.
Microcentrifuge Tubes.
De-ionized or distilled water.
Absorbent paper for blotting the microplate.
Container for Wash Solution.
0.01 mol/L (or 1x) Phosphate Buffered Saline (PBS), pH 7.0-7.2.

STORAGEAll the reagents should be kept according to the labels on vials. The Calibrator, Detection Reagent A,
Detection Reagent B and the 96-well strip plate should be stored at -20°C upon receipt while the others
should be at 4°C. The unused strips should be kept in a sealed bag with the desiccant provided tominimize exposure to damp air. Opened test kits will remain stable for 1 month, provided it is stored as
described above.

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KAMIYA BIOMEDICAL COMPANYTEST PRINCIPLE
The microplate provided in this kit has been pre-coated with an antibody specific to IDE. Calibrators or
samples are then added to the appropriate microplate wells with a biotin-conjugated antibody specific to
IDE. Next, Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well andincubated. After TMB substrate solution is added, only those wells that contain IDE, biotin-conjugatedantibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is
terminated by the addition of sulphuric acid solution and the color change is measured
spectrophotometrically at a wavelength of 450 nm ± 10 nm. The concentration of IDE in the samples isthen determined by comparing the O.D of the samples to the calibration curve.

SAMPLE COLLECTION AND STORAGE
Serum
Use a serum separator tube and allow samples to clot for two hours at room temperature or overnight at
4°C before centrifugation for 20 minutes at approximately 1,000 x g. Assay freshly prepared serum
immediately or store samples in aliquot at -20°C or -80°C for later use. Avoid repeated freeze/thaw
cycles.

PlasmaCollect plasma using EDTA or heparin as an anticoagulant. Centrifuge samples for 15 minutes at 1,000 x
g at 4°C within 30 minutes of collection. Remove plasma and assay immediately or store samples inaliquot at -20°C or -80°C for later use. Avoid repeated freeze/thaw cycles.

Tissue homogenates
The preparation of tissue homogenates will vary depending upon tissue type.
1. Tissues were rinsed in ice-cold PBS to remove excess blood thoroughly and weighed before
homogenization.
2. Minced the tissues to small pieces and homogenized them in fresh lysis buffer (different lysis buffer
needs to be chosen based on subcellular location of the target protein) (w:v = 1:20-1:50, e.g. 1 mL lysis
buffer is added in 20-50 mg tissue sample) with a glass homogenizer on ice (Micro Tissue Grinders
works, too).
3. The resulting suspension was sonicated with an ultrasonic cell disrupter till the solution is clarified.
4. Then, the homogenates were centrifuged for 5 minutes at 10,000 × g. Collect the supernates andassay immediately or aliquot and store at ≤-20°C.

Cell Lysates
Cells need to be lysed before assaying according to the following directions.
1. Adherent cells should be washed by cold PBS gently, and then detached with trypsin, and collected bycentrifugation at 1,000 x g for 5 minutes (suspension cells can be collected by centrifugation directly).
2. Wash cells three times in cold PBS.
7
3. Resuspend cells in fresh lysis buffer with concentration of 10 cells/mL. If it is necessary, the cells could
be subjected to ultrasonication till the solution is clarified.
4. Centrifuge at 1,500 x g for 10 minutes at 4°C to remove cellular debris. Assay immediately or aliquot
and store at ≤-20°C.

Cell culture supernates and other biological fluids
Centrifuge samples for 20 minutes at 1,000 x g. Collect the supernates and assay immediately or store
samples in aliquot at -20°C or -80°C for later use. Avoid repeated freeze/thaw cycles.

Note:
1. Samples to be used within 5 days may be stored at 4°C, otherwise samples must be stored at -20°C(≤1 month) or -80°C (≤2 months) to avoid loss of bioactivity and contamination.
2. When performing the assay, bring samples to room temperature.
3. Sample hemolysis will influence the result, so hemolytic specimen should not be used.
4. It is highly recommended to use serum instead of plasma for the detection based on quantity of our
in-house data.
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REAGENT PREPARATION
Bring all kit components and samples to room temperature (18-25°C) before use. If the kit will not be used
up in one time, please only take out strips and reagents for present experiment, and leave the remaining
strips and reagents in required condition.

Calibrator
Reconstitute the Calibrator with 1.0 mL of Calibrator Diluent, kept for 10 minutes at room temperature,
shake gently (not to foam). The concentration of the calibrator in the stock solution is 100 ng/mL. Please
prepare 7 tubes containing 0.5 mL Calibrator Diluent and produce a double dilution series according to
the picture shown below. Mix each tube thoroughly before the next transfer. Set up 7 points of diluted
calibrator such as 100 ng/mL, 50 ng/mL, 25 ng/mL, 12.5 ng/mL, 6.25 ng/mL, 3.12 ng/mL, 1.56 ng/mL, andthe last EP tube with Calibrator Diluent is the blank as 0 ng/mL.

Tube
ng/mL

1
100

2
50

3
25

4
12.5

5
6.25

6
3.12

7
1.56

8
0

Detection Reagent A and Detection Reagent B
Briefly spin or centrifuge the stock Detection A and Detection B before use. Dilute them to the working
concentration 100-fold with Assay Diluent A and B, respectively.

Wash Solution
Dilute 20 mL of Wash Solution concentrate (30X) with 580 mL of de-ionized or distilled water to prepare
600 mL of Wash Solution (1X).

TMB substrate
Aspirate the needed dosage of the solution with sterilized tips and do not dump the residual solution into
the vial again.

Note:
1. Prepare calibrators within 15 minutes before assay. Please do not dissolve the reagents at 37°C
directly.
2. Making serial dilution in the wells directly is not permitted.
3. Please carefully reconstitute Calibrators or working Detection Reagent A and B according to the
instruction, and avoid foaming and mix gently until the crystals are completely dissolved. To minimize
imprecision caused by pipetting, use small volumes and ensure that pipettors are calibrated. It is
recommended to suck more than 10 µL for one pipetting.
4. The reconstituted Calibrators, Detection Reagent A and Detection Reagent B can be used onlyonce.
5. If crystals have formed in the Wash Solution concentrate (30X), warm to room temperature and mix
gently until the crystals are completely dissolved.
6. Contaminated water or container for reagent preparation will influence the detection result.

SAMPLE PREPARATION
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1. We are only responsible for the kit itself, but not for the samples consumed during the assay. The
user should calculate the possible amount of the samples used in the whole test. Please reserve
sufficient samples in advance.
2. Please predict the concentration before assaying. If values for these are not within the range of thecalibration curve, users must determine the optimal sample dilutions for their particular experiments.
Sample should be diluted by PBS.
3. If the samples are not indicated in the manual, a preliminary experiment to determine the validity of
the kit is necessary.
4. Tissue or cell extraction samples prepared by chemical lysis buffer may cause unexpected ELISA
results due to the impacts from certain chemicals.
5. Due to the possibility of mismatching between antigen from other origin and antibody used in our kits
(e.g., antibody targets conformational epitope rather than linear epitope), some native or recombinant
proteins from other manufacturers may not be recognized by our products.
6. Influenced by the factors including cell viability, cell number or sampling time, samples from cell
culture supernatant may not be detected by the kit.
7. Fresh samples without long time storage are recommended for the test. Otherwise, protein
degradation and denaturalization may occur in those samples and finally lead to wrong results.

ASSAY PROCEDURE
1. Determine wells for diluted calibrator, blank and sample. Prepare 7 wells for calibrator, 1 well forblank. Add 100 µL each of dilutions of calibrator (read Reagent Preparation), blank and samples into
the appropriate wells. Cover with the Plate sealer. Incubate for 1 hour at 37°C.
2. Remove the liquid of each well, don’t wash.
3. Add 100 µL of Detection Reagent A working solution to each well, cover the wells with the plate
sealer and incubate for 1 hour at 37°C.
4. Aspirate the solution and wash with 350 µL of 1X Wash Solution to each well using a squirt bottle,
multi-channel pipette, manifold dispenser or autowasher, and let it sit for 1~2 minutes. Remove theremaining liquid from all wells completely by snapping the plate onto absorbent paper. Totally wash 3
times. After the last wash, remove any remaining Wash Buffer by aspirating or decanting. Invert theplate and blot it against absorbent paper.
5. Add 100 µL of Detection Reagent B working solution to each well, cover the wells with the plate
sealer and incubate for 30 minutes at 37°C.
6. Repeat the aspiration/wash process for total 5 times as conducted in step 4.
7. Add 90 µL of Substrate Solution to each well. Cover with a new Plate sealer. Incubate for 10 - 20
minutes at 37°C (Don’t exceed 30 minutes). Protect from light. The liquid will turn blue by the additionof Substrate Solution.
8. Add 50 µL of Stop Solution to each well. The liquid will turn yellow by the addition of Stop solution.
Mix the liquid by tapping the side of the plate. If color change does not appear uniform, gently tap theplate to ensure thorough mixing.
9. Remove any drop of water and fingerprint on the bottom of the plate and confirm there is no bubble
on the surface of the liquid. Then, run the microplate reader and conduct measurement at 450 nm
immediately.
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Note:
1. Assay preparation: Keep appropriate numbers of wells for each experiment and remove extra wellsfrom microplate. Rest wells should be resealed and stored at -20°C.
2. Samples or reagents addition: Please use the freshly prepared Calibrator. Please carefully add
samples to wells and mix gently to avoid foaming. Do not touch the well wall. For each step in theprocedure, total dispensing time for addition of reagents or samples to the assay plate should notexceed 10 minutes. This will ensure equal elapsed time for each pipetting step, without interruption.
Duplication of all calibrators and specimens, although not required, is recommended. To avoid crosscontamination, change pipette tips between additions of calibrators, samples, and reagents. Also, use
separated reservoirs for each reagent.
3. Incubation: To ensure accurate results, proper adhesion of plate sealers during incubation steps isnecessary. Do not allow wells to sit uncovered for extended periods between incubation steps. Oncereagents are added to the well strips, DO NOT let the strips DRY at any time during the assay.
Incubation time and temperature must be controlled.
4. Washing: The wash procedure is critical. Complete removal of liquid at each step is essential to good
performance. After the last wash, remove any remaining Wash Solution by aspirating or decanting
and remove any drop of water and fingerprint on the bottom of the plate. Insufficient washing will
result in poor precision and falsely elevated absorbance reading.
5. Controlling of reaction time: Observe the change of color after adding TMB Substrate (e.g.
observation once every 10 minutes), if the color is too deep, add Stop Solution in advance to avoid
excessively strong reaction which will result in inaccurate absorbance reading.
6. TMB Substrate is easily contaminated. Please protect it from light.
7. The environment humidity which is less than 60% might have some effects on the final performance,
therefore, a humidifier is recommended to be used at that condition.

CALCULATION OF RESULTS
Average the duplicate readings for each calibrator, control, and samples and subtract the average zero
calibrator optical density. Construct a calibration curve by plotting the mean O.D. and concentration foreach calibrator and draw a best fit curve through the points on the graph or create a calibration curve on
log-log graph paper with IDE concentration on the y-axis and absorbance on the x-axis. Using some plot
software is also recommended. If samples have been diluted, the concentration read from the calibration
curve must be multiplied by the dilution factor.

PERFORMANCE
Detection Range
1.56-100 ng/mL.
The calibration curve concentrations used for the ELISA’s were 100 ng/mL, 50 ng/mL, 25 ng/mL, 12.5
ng/mL, 6.25 ng/mL, 3.12 ng/mL, 1.56 ng/mL.

Sensitivity
The minimum detectable dose of IDE is typically less than 0.59 ng/mL.
The sensitivity of this assay, or Lower Limit of Detection (LLD) was defined as the lowest protein
concentration that could be differentiated from zero. It was determined by adding two standard deviations
to the mean optical density value of twenty zero calibrator replicates and calculating the corresponding
concentration.

Specificity
This assay has high sensitivity and excellent specificity for detection of IDE.
No significant cross-reactivity or interference between IDE and analogues was observed.
Note:

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Limited by current skills and knowledge, it is impossible for us to complete the cross-reactivity detection
between IDE and all the analogues, therefore, cross reaction may still exist.

ASSAY PROCEDURE SUMMARY
1.
2.
3.
4.
5.
6.
7.
8.

Prepare all reagents, samples and calibrators;
Add 100 µL calibrator or sample to each well. Incubate 1 hour at 37°C;
Aspirate and add 100 µL prepared Detection Reagent A. Incubate 1 hour at 37°C;
Aspirate and wash 3 times;
Add 100 µL prepared Detection Reagent B. Incubate 30 minutes at 37°C;
Aspirate and wash 5 times;
Add 90 µL Substrate Solution. Incubate 10-20 minutes at 37°C;
Add 50 µL Stop Solution. Read at 450 nm immediately.

IMPORTANT NOTE
1. The final experimental results will be closely related to validity of the products, so the kit should be
used prior to the expiration date. And please store the kits exactly according to the instruction.
2. Kits from different batches may be a little different in detection range, sensitivity and color developing
time. Please perform the experiment exactly according to the instruction attached in kit while electronic
ones from our website is only for reference.
3. Do not mix or substitute reagents from one kit lot to another. Use only the reagents supplied bymanufacturer.
4. Protect all reagents from strong light during storage and incubation. All the bottle caps of reagentsshould be covered tightly to prevent the evaporation and contamination of microorganism. TMB Substrateshould remain colorless till it is reacted with the enzyme which binds to the microplate.
5. There may be some foggy substance in the wells when the plate is opened at the first time. It will nothave any effect on the final assay results. Do not remove microplate from the storage bag until needed.
6. Wrong operations during the reagents preparation and loading, as well as incorrect parameter setting
for the plate reader may lead to incorrect results. A microplate reader with a bandwidth of 10 nm or lessand an optical density range of 0-3 O.D. at 450 ± 10 nm wavelength is acceptable for use in absorbancemeasurement. Please read the instruction carefully and adjust the instrument prior to the experiment.
7. Variation in sample preparation and each step of experimental operation may cause different results. In
order to get better reproducible results, the operation of each step in the assay should be controlled.
8. Each kit has been strictly passed Q.C test. However, results from end users might be inconsistent with
our in-house data due to some unexpected transportation conditions or different lab equipments. Intraassay variance among kits from different batches might arise from above factors, too.
9. Kits from different manufacturers with the same item might produce different results, since we haven’t
compared our products with other manufacturers.
10. The calibrator of the kit and immunogen used for antibody preparation are commonly recombinant
proteins, as different fragments, expression systems, purification methods might be used in recombinant
protein preparation, we can not guarantee the kit could detect recombinant protein from other companies.
So, it is not recommended to use the kit for the detection of recombinant protein.
11. Please predict the concentration of target molecules in samples, or arrange a preliminary experiment,
it is a good way to solve specific problem, e.g. the concentration of samples are beyond the detection
range of the kit.
12. The kit might not be suitable for detection of samples from some special experiment, for instance,
knock-out experiments, due to their uncertainty of effectiveness.
13. The Stop Solution suggested for use with this kit is an acid solution. Wear eye, hand, face, andclothing protection when using this material.

FOR RESEARCH USE ONLY.

KAMIYA BIOMEDICAL COMPANY
12779 Gateway Drive, Seattle, WA 98168
Tel: (206) 575-8068 Fax: (206) 575-8094
Email: LifeScience@k-assay.com
www.k-assay.com

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