Pullulan encapsulation of labile biomolecules to give stable bioassay tablets.
A simple and inexpensive method is reported for the long-term stabilization of enzymes and other unstable reagents in premeasured quantities in water-soluble tablets (cast, not compressed) made with pullulan, a nonionic polysaccharide that forms an oxygen impermeable solid upon drying. The pullulan tablets dissolve in aqueous solutions in seconds, thereby facilitating the easy execution of bioassays at remote sites with no need for special reagent handling and liquid pipetting. This approach is modular in nature, thus allowing the creation of individual tablets for enzymes and their substrates. Proof-of-principle demonstrations include a Taq polymerase tablet for DNA amplification through PCR and a pesticide assay kit consisting of separate tablets for acetylcholinesterase and its chromogenic substrate, indoxyl acetate, both of which are highly unstable. The encapsulated reagents remain stable at room temperature for months, thus enabling the room-temperature shipping and storage of bioassay components.
Departments of Chemical Engineering, Chemistry & Chemical Biology, and Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4M1 (Canada).
Sana
S
Jahanshahi-Anbuhi
Kevin
K
Pennings
Vincent
V
Leung
Meng
M
Liu
Carmen
C
Carrasquilla
Balamurali
B
Kannan
Yingfu
Y
Li
Robert
R
Pelton
John D
JD
Brennan
Carlos D M
CD
Filipe
D001681:Biological Assay; D002241:Carbohydrates; D005936:Glucans / Q000737:chemistry*; D013607:Tablets
D002241:Carbohydrates; D005936:Glucans; D013607:Tablets; C009109:pullulan
carbohydrates; encapsulation; enzymes; pullulan; stabilization