Table 2.

Enrichment of phage particles against SARS-CoV-2-spike and -RBD specific nanobodies during four rounds of panning

Round of screening	Input (pfu/well)	P output (pfu/well)		N output (pfu/well)		Recovery (P/input)		P/N
		S	RBD	S	RBD	S	RBD	S	RBD
1st round	1.0 × 1011	1.5 × 104	1.4 × 104	8.4 × 103	9.1 × 103	1.5 × 10− 7	1.4 × 10− 7	17.8	1.5
2nd round	1.0 × 1011	6.5 × 105	3.4 × 105	3.4 × 103	2.9 × 103	6.5 × 10− 6	3.4 × 10− 6	1.9 × 102	1.2 × 102
3rd round	1.0 × 1011	2.6 × 107	1.9 × 107	4.5 × 104	3.8 × 104	2.6 × 10− 4	1.9 × 10− 4	5.7 × 102	5.0 × 102
4th round	1.0 × 1011	5.4 × 108	5.2 × 108	3.6 × 105	2.7 × 105	5.4 × 10− 2	5.2 × 10− 2	1.5 × 103	1.8 × 103