scholarly journals Magnetic Bead Separation

2020 ◽  
Author(s):  
Keyword(s):  
Magnetic Bead ◽  
Magnetic Bead Separation

Interference-free SERS tags for ultrasensitive quantitative detection of tyrosinase in human serum based on magnetic bead separation

2020 ◽  
Vol 1138 ◽  
pp. 150-157
Author(s):  
Dechan Lu ◽  
Xueliang Lin ◽  
Cairou Chen ◽  
Yudong Lu ◽  
Shangyuan Feng ◽  
...  
Keyword(s):  
Human Serum ◽  
Magnetic Bead ◽  
Quantitative Detection ◽  
Magnetic Bead Separation ◽  
Sers Tags

scholarly journals Isolation of High-Affinity Single-Chain Antibodies against Mycobacterium avium subsp. paratuberculosis Surface Proteins from Sheep with Johne's Disease

2006 ◽  
Vol 13 (9) ◽  
pp. 1022-1029 ◽  
Author(s):  
Sven Berger ◽  
Dominik Hinz ◽  
John P. Bannantine ◽  
J. Frank T. Griffin
Keyword(s):  
Mycobacterium Avium ◽  
Magnetic Bead ◽  
Johne's Disease ◽  
Johne’S Disease ◽  
Surface Proteins ◽  
Broth Culture ◽  
Economic Losses ◽  
Single Chain ◽  
Single Chain Antibodies ◽  
Magnetic Bead Separation

ABSTRACT Johne's disease, caused by infection with Mycobacterium avium subsp. paratuberculosis, causes significant economic losses to the livestock farming industry. Improved investigative and diagnostic tools—necessary to understand disease processes and to identify subclinical infection—are much sought after. Here, we describe the production of single-chain antibodies with defined specificity for M. avium subsp. paratuberculosis surface proteins. Single-chain antibodies (scFv) were generated from sheep with Johne's disease by cloning heavy-chain and lambda light-chain variable regions and expressing these in fusion with gene III of filamentous phages. Two scFv clones (designated SurfS1.2 and SurfS2.2) were shown to be immunoreactive against M. avium subsp. paratuberculosis surface targets by flow cytometry, and immunoblotting identified specificity for a 34-kDa proteinase-susceptible determinant. Both antibodies were cross-reactive against Mycobacterium avium subsp. avium but nonreactive against Mycobacterium bovis or Mycobacterium phlei cells and were shown to be capable of enriching M. avium subsp. paratuberculosis cells by a factor of approximately 106-fold when employed in magnetic bead separation of mixed Mycobacterium sp. cultures. Further, magnetic bead separation using SurfS1.2 and SurfS2.2 was capable of isolating as few as 103 M. avium subsp. paratuberculosis cells from ovine fecal samples, indicating the diagnostic potential of these reagents. Finally, inclusion of SurfS1.2 or SurfS2.2 in in vitro broth culture with M. avium subsp. paratuberculosis indicated that surface binding activity did not impede bacterial growth, although colony clumping was prevented. These results are discussed in terms of the potential use of single-chain phage display monoclonal antibodies as novel diagnostic reagents.

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