Biological laser printing as an alternative to traditional protein arrayers

Current proteomics experiments often rely upon printing techniques such as ink jet, pin, or quill arrayers that were developed for the creation of cDNA microarrays. These techniques often do not meet the spotting requirements needed for successful high throughput protein identification and profiling. The Naval Research Laboratory has developed an alternative to these commercially available arrayers that does not rely upon a solid pin or capillary-based fluidics. This presentation describes experiments demonstrating that biological laser printing, or BioLP (TM) is capable of depositing microarrays of proteins rapidly and efficiently. This technique utilizes a focused laser pulse to obtain micron-scale resolution rather than a pin or orifice, thereby eliminating clogging and protein loss commonly encountered in commercially available printers. The speed and spot-to-spot reproducibility of the printer is comparable to other techniques, while the minimum spot diameter and volume per printed droplet is significantly less at 30 microns and similar to 500 fL, respectively. The transfer of fluid by BioLP occurs through a fluid jetting mechanism, as observed by high-speed images of the printing process. In addition, printed biotinylated bovine serum albumin is identified through immunoassay and observed by fluorescent detection. These results indicate that BioLP holds promise as a novel protein printer for use in. a wide range of applications in the proteomics field.