The Test it @ home/BOSON rapid antibody test consists of a chromatographic strip (to which various reagents are attached) in a plastic holder in which three cutouts are present: S (a small round opening where a running liquid can be dripped), S1 (where a blood sample can be applied) and a large oblong rectangular window where the letters M, G and C are printed on the right side of the plastic. If (10-12 minutes after application of blood sample in S1 and two drops of running liquid at position S) on the white area next to the letter M a magenta colored horizontal line appears then in the blood sample IgM has been detected, if next to the letter G a horizontal line appears then in the blood sample IgG has been detected and if next to the letter C a line appears the user has an indication for correct execution of the test.
Composition of the test kit
The Test it @ home COVID-19 IgG/IgM test kit consists of the following items: Manual, BOSON Covid-19 IgG/IgM test card, alcohol swab, capillary, finger prick lancet and a buffer ampoule.
Test Output
Step-by-step plan Test it @ home COVID-19 IgG/IgM antibody test
- Remove all the material from the bag and display in this order: Covid test, alcohol cloth, finger pricker, capillary (transparent tube) and buffer ampoule.
- Remove the Covid test from the packaging.
- Take your dominant hand (if you are right handed, test on your left hand). Choose a finger, preferably the index finger.
- Make sure there is a good blood flow in the finger by stimulating your blood vessels. You do this by a push and squeeze movement along the finger.
- Clean the relevant finger with the alcohol cloth.
- Punch on de side of the finger (beware to put enough pressure on the finger to get a proper blood droplet).
- Use the capillary to suck up the blood. Keep it in such a way that the black line points to the finger and squeeze the capillary. Gently press the tube to the blood droplet and release the pressure. This will cause the blood to enter the tube. Fill the tube till the black line.
- Transfer the contents of the capillary into the small squared box (S1).
- Add 2 free falling droplets of the buffer in the large round box (S).
- Clean your finger with the alcohol cloth.
- Wait for 10 minutes and immediately read the results.
Results
Meaning of results
Below is a diagram of the progression of Covid-19 antibodies after infection. The first symptoms of a Covid-19 infection are the starting point of an increase of IgM antibodies in the blood and about 7 days later the IgG antibody level rises. Some days after the IgG antibody level increases, the IgM level decreases. The presence of an IgM band in the absence of an IgG band, or a weak IgG band, may mean that the patient is still in the infectious phase of Covid-19: In this case a Covid-19 PCR virus test should be performed to determine the status.
Progression of antibody levels following an infection with the Covid-19 virus: After infection, an incubation period of about 10 days follows, the contagious period starts about 6 days after infection. After the incubation period of 10 days the first symptoms (like fever) appear and this is also the starting point for the appearance of the antibody IgM in the blood of Covid-19 patients. About 7 days after the first symptoms the level of the antibody IgG in the blood rises, about 4 days later the IgM level drops, while the IgG level continues to rise and remains present in the blood for a long time. The drop in the IgM level coincides roughly with the end of the contagious period.
Test Characteristics
Test characteristics were determined in a study of the BOSON Rapid 2019-nCoV IgG/IgM Combo Test Card on 200 clinically positive and 192 clinically negative human sera.
A number of clinically positive and negative samples were tested in 6-fold to check or establish the repeatability of the rapid test.
A twofold dilution series of a clinically strongly positive IgG and a strongly positive IgM sample in a pool of clinically negative samples gives an impression of the analytical sensitivity of the rapid test.
A number of patients with known Corona infection status were followed over time to study the progression of antibody levels.
The BOSON Covid-19 IgG/IgM test cards give good results: Sensitivity SE is high at 96% (95% CI 93.3-98.7%), with excellent specificity SP of 99.5% (95% CI 98.5-100%) and accuracy AC of 97.7% (95% CI 96.2-99.1%). Reproducibility of the results is good, so is the analytical sensitivity of the test. In addition, the test can be used to follow up or check accumulated antibody levels after infection or vaccination.
