Table 2 Overview of the available enrichment strategies.

Subtractive selection

Eliminating cells that do not express target proteins prior to selection

scFv

Targeted cells/leukocytes,

~3.5 fold

N/A

N/A

+

+

de Kruif, et al.⁶⁴

Depletion selection ‘BRASIL’

Depleting non-antigen binders prior to selection

Peptide

vascular endothelial growth factor (VEGF),

2–3 fold

N/A

N/A

+

+

Giordano, et al.⁶⁵

Subtraction/depletion

Removing unwanted epitopes prior to selection

scFv

Glycoprotein IIb/IIIa,

2–5 fold

N/A

N/A

+

N/A

Eisenhardt, et al.⁶⁶

Microselection/shadow-stick selection

Targeting a single rare cell and ultra-violet (UV) inactivation of the non-binders

scFv

Targeted rare cells,

10–25%

N/A

N/A

+

+

Sørensen, et al.⁶⁷

Sørensen M. D. and Kristensen P.⁶⁸

Masked selection

Using non-relevant soluble binders to block non-relevant epitopes prior to selection

VHH

Recombinant HER2-Fc Protein, 92.6%

+

N/A

N/A

N/A

Even-Desrumeaux, et al.⁶⁹

HER2 receptor, 26%

N/A

N/A

+

+

mGluR4 receptor, 90%

N/A

N/A

+

+

CXCR4 receptor, 24%

N/A

N/A

+

+

Breast Cancer Biopsy Lysates, 40%

N/A

+

+

+

Cell Surface Binders on Breast Cancer Cell Lines, 60%

N/A

N/A

+

+

Negative selection

Eliminating dead cells and cell debris prior to selection

scFv

61% intact cells recovered

+

N/A

+

+

Pavoni, et al.⁷⁰

Subtractive selection

Removing non-binders using non-transfected cells prior to selection

scFv

Membrane bound antigens,

4–5 fold

N/A

N/A

+

+

Jones, et al.⁷¹

‘Yin-Yang’

Using target -unrelated proteins to preoccupy non-specific binders prior to selection

scFv

rMERS-NP,

2.5 fold/41.7%

+

+

N/A

N/A

This study