Guidelines for sample prepration
IMPORTANT! Reagents are lot specific. Do not mix or exchange
reagent between lots or from dierent kits.
• Collect samples in pyrogen/endotoxin-free tubes.
• Freeze samples at −20°C after collection if samples will not
be tested immediately. Avoid multiple freeze-thaw cycles of
frozen samples.
• Thaw sample completely, keep on ice and mix well prior to
analysis.
Required materials not supplied
• Distilled or deionized water
• Calibrated adjustable precision pipettes
• Mixer or shaker (e.g., HulaMixer™ Sample Mixer)
• ELISA plate reader with software capable of measurement
at 450 nm, 490 nm, and 650 nm (e.g., Varioskan™ LUX
Multimode Microplate Reader)
See “Automated protocol using the KingFisher™ Flex instrument”,
or “Manual protocol using a DynaMag™ magnet” for additional
materials required for the respective procedures.
Before you begin
• Allow Wash Buer (20X) and Assay Buer (20X) to reach
room temperature before use.
• Dilute buers before use. Mix concentrated buers to re-
dissolve any precipitated salts.
Note: All buers are supplied in excess.
• Do not allow the beads to settle to the bottom of the vial
when dispensing them into the plate wells. Resuspend the
beads with a pipette prior to transferring them into each well.
Prepare 1X Wash Buer
1. Dilute 25 mL of Wash Buer (20X) with 475 mL of deionized
or distilled water. Label as 1X Wash Buer.
2. Store 1X Wash Buer at 2–8℃. Use 1X Wash Buer within
30 days.
Prepare 1X Assay Buer
1. Dilute 5 mL of Assay Buer (20X) with 95 mL of deionized or
distilled water. Label as 1X Assay Buer.
2. Store 1X Assay Buer at 2–8℃. Use 1X Assay Buer within
30 days.
Resuspend Dynabeads™ magnetic beads
1. Resuspend the magnetic beads in the vial by vortexing
for at least 30 seconds or using a tilt-and-rotate mixer for
5 minutes.
2. Leave the vial on a mixer to keep the beads resuspended
until ready to use.
Reconstitute controls
• High, Calibrator, and Low control antibodies are provided for
use in the assay.
• The reconstitution volume for each control is indicated on the
respective label of each vial.
1. Centrifuge the tubes before use to collect the lyophilized
powder at the bottom of the tubes.
2. Add the volume of deionized or distilled water indicated on
the label of each vial to achieve the following concentrations:
• Human SARS-CoV-2 IgG
High Control: 150,000 pg/mL
• Human SARS-CoV-2 IgG
Calibrator: 37,500 pg/mL
• Human SARS-CoV-2 IgG
Low Control: 9,375 pg/mL
3. Swirl or mix the tubes gently, then incubate for 10 minutes.
For optimal results, keep the vials on ice until ready to use.
Prepare 1X HRP Conjugate Solution
Note: Prepare 1X HRP Conjugate Solution within 15 minutes of
usage.
1. For each plate, dispense 120 μL of Human SARS-CoV-2 IgG
HRP Conjugate (100X) into a tube containing 11.88 mL of 1X
Assay Buer to make the 1X HRP Conjugate Solution.
2. Mix thoroughly. Keep away from light.
Pre‑dilute samples
For best results, pre‑dilute serum and plasma samples prior to
the experiment. High titers of immunoglobulins in the samples can
result in absorbance values outside of the assay range. Because
Human SARS-CoV-2 IgG titers can be very high, each investigator
should determine the optimal dilution appropriate for the type of
assay (qualitative or quantitative) being performed.
Qualitative assays
Note: See Figure 2 for recommended plate layout and “Determine
results for qualitative assay” on page 6 for how to interpret the
results.
• Sample dilution
The results of the assay are determined by comparing the
signal in the sample to the signal from the Calibrator. Dilute
serum and plasma samples ~1:500 with 1X Assay Buer to
achieve the highest sensitivity, but the dilution factor should
be optimized depending on the immunoglobulin titer.
• Antibody dilution
Dilute the resuspended High, Calibrator, and Low Controls
1:10 in 1X Assay Buer. If running 3 replicates, prepare
400 µL of solution (add 40 µL of control to 360 µL of 1X
Assay Buer).
2Dynabeads™ SARS-CoV-2 Spike IgG ELISA Kit User Guide