text: The advantages of reverse transfection (over conventional transfection) are: 
  *The addition and attachment of target cells to the DNA-loaded surface can lead to a higher probability of cell-DNA contact, potentially leading to higher transfection efficiency.
  *Labour-saving materials (less DNA is required)
  *High-throughput screening; hundreds of genes may be expressed in cells on a single microarray for studying gene expression and regulation.
  *Parallel cell seeding in a single chamber for 384 experiments, with no physical separation between experiments, increases screening data quality. Well-to-well variations occur in experiments performed in multi-wall dishes.
  *Exact-replicate arrays may be produced, since the same sample source plate may be dried and printed on different slides for at least 15 months' storage without apparent loss of transfection efficiency. 
  The disadvantages of reverse transfection are: 
  *Reverse transfection is more expensive because a highly accurate and efficient microarray printing system is needed to print the DNA-gelatin solution onto the slides. 
  *Applications with different cell lines have (so far) required protocol variations to manufacture siRNA or plasmid arrays, which involve considerable development and testing.
  *Increased possibility of array-spot cross-contamination as spot density increases; therefore, optimization of the array layout is important.