This video demonstrates an in vitro technique to study the effect of antibodies on fungal biofilms. The pathogenic fungus Candida tropicalis secretes a virulence factor secreted aspartyl proteinase 2 (Sap2), facilitating biofilm formation. Upon introducing a heat-inactivated serum containing Sap2-specific antibodies that inhibit biofilm maturation, the viability of the fungal cells is assessed using a chromogenic assay.
Protocol
1. C. tropicalis biofilm formation Prepare Candida biofilms in a 96-well flat-bottomed polystyrene microtiter plate as described earlier (Figure 1). Add 100 µL of C. tropicalis culture (from 106 cells/mL stock, prepared as above) to a 96-well microtiter plate using a multichannel pipette (Figure 2A). Keep the last two columns (11 and 12) as 'no fungus plus …
Representative Results
Figure 1: Imaging Candida tropicalis biofilm. (A) Visualization of Candida tropicalis biofilm formed on the bottom of a 96-well microtiter plate after removal of RPMI medium, using an inverted microscope. The image was captured using brightfield microscopy (no stain was used). (B) Visualization of C. tropicalis<…
Divulgations
The authors have nothing to disclose.
Materials
15 mL conical centrifuge tubes
BD Falcon
546021
1x PBS
–
Prepared in lab
NaCl : 4 g
KCl : 0.1 g
Na2HPO4: 0.72 g
KH2PO4 : 0.12 g
Water 500 mL. Adjust pH to 7.4
50 mL conical centrifuge tubes
BD Falcon
546041
96-well microtiter plates
Nunc
442404
Incubator
Generic
Menadione
Sigma
M5625
Microtiter Plate Reader
Generic
Multichannel pipette and tips
Generic
Petri dishes
Tarson
460090
Ringers Lactate
–
Prepared in lab
sodium chloride 0.6 g sodium lactate 0.312 g potassium chloride 0.035 g calcium chloride 0.027 g Water 100 mL. Adjust to pH 7.0