Table 2.

Competitive binding of SARS-CoV-2 spike protein S1, anticoagulation factors AT and HCII to heparin on microarrays.

Competitive binding experiments	Residual bindinga		Residual bindingb
	AT	S1	HCII	S1
i) with premixed S1 & AT/HCII	96.4% ± 23.1%	62.0% ± 12.5%	73.3% ± 15.6%	25.8% ± 0.5%
ii) with AT/HCII followed by S1	104.8% ± 18.7%	24.3% ± 1.7%	76.9% ± 13.0%	11.4% ± 2.0%
iii) with S1 followed by AT/HCII	76.3% ± 21.0%	67.0% ± 27.8%	78.5% ± 11.4%	92.7% ± 18.0%

Means and standard deviations were obtained from 8 replicate points and three parallel experiments. The ratio of the mean value of the competition experiment to that of the control experiment was calculated shown as percentage to indicate the degree of S protein competition.

^aConcentrations used: S1 (2 μg/mL) and AT (1 μg/mL).

^bConcentration used: S1 (4 μg/mL) and HCII (2 μg/mL).