title: Efficient non-viral transfection of primary human adult chondrocytes in a high-throughput format.
abstract: OBJECTIVE
  The development of a reliable high-throughput transfection protocol for primary human articular chondrocytes.
  
  
  METHODS
  Primary human chondrocytes were isolated from adult knee cartilage by an optimized enzymatic digestion protocol and cultivated in high-density monolayer culture for 3-5 days. Isolated chondrocytes were transfected with a green fluorescent protein (GFP)-expressing reporter construct using amaxa's Nucleofector 96-well Shuttle System. Transfection efficiencies were measured by fluorescence activated cell sorting and cell viability was determined by an adenosine-5'-triphosphate (ATP) assay. siRNA oligonucleotides (against glyceraldehyde-3-phosphate dehydrogenase (GAPDH)) were transfected into the cells using the optimized nucleofection protocol and mRNA knockdown values were determined by a branched-DNA assay.
  
  
  RESULTS
  Transfection efficiencies of more than 70% of surviving cells were achieved routinely with the nucleofection protocol presented in this article. Cell viability 24h post transfection was around 80%. The cell number used per transfection was reduced to 2x10(5) per sample. In addition, the protocol proved to be well suited for the transfer of siRNA molecules into primary human chondrocytes with suppression rates on the mRNA level of more than 95% (for GAPDH).
  
  
  CONCLUSIONS
  We present the successful use of nucleofection on primary human chondrocytes using a microtiter plate compatible format that for the first time allows the efficient transfection of up to 96 samples in parallel. The optimized nucleofection protocol is offering maximum substrate flexibility by allowing transfer of DNA and siRNA oligonucleotides with the same set of parameters. Moreover, the transfection procedure requires substantially lower cell numbers than single cuvette protocols and is therefore perfectly suited for applications requiring multiple experimental replicates.
authors.affiliation: Institute of Pathology, University Hospital Leipzig, Leipzig, Germany. jochen.haag@medizin.uni-leipzig.de
authors.forename: J
authors.initials: J
authors.lastname: Haag
authors.forename: R
authors.initials: R
authors.lastname: Voigt
authors.forename: S
authors.initials: S
authors.lastname: Soeder
authors.forename: T
authors.initials: T
authors.lastname: Aigner
mesh_terms: D002358:Cartilage, Articular / Q000473:pathology*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism*; D005434:Flow Cytometry / Q000379:methods; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D014162:Transfection
chemical_list: D049452:Green Fluorescent Proteins