Fluorescent probes of life: Delivery system

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Fluorescent probes of lifeDelivery system

• Life in the Atacama Design ReviewDecember 19,
  2003
• WaggonerCMU

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Description and Motivation

• Fluorescent probe delivery system
• Must place 4 different dyes within cell
  structures of biofilm or spores or exposed cells

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Key Requirements

• Place 4 fluorescent probes on DNA, protein, lipid
  and carbohydrate components of cells
• - Softening of cell encapsulation structures
• - Delivery of probes
• - Possible wash step
• Delivery to exposed rock or soil below camera
• Good coverage without getting probes in detection
  optics
• Robust, low energy, small size

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Design Considerations

• Three containers for spritzed components
• Nozzles for directed spray
• Corrosion-resistant strong tubing
• Pressure or pump delivery system
• Pump requires energy est. 10W for 3 min
• Alternative compressed air with switches
• Sufficient dye must be delivered to cell
  components timing and flow rate Rover
  electronics
• Carrier solvents for the three sprays
• The fluorescent probe selection separate design

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Technical approach

• Spritz 1 Sample preparation
• - Soften secreted coatings, permeabilize cells
• - Incubate 5 min to 2 hr to be determined
• Spritz 2 Fluorescent probe delivery
• - Probably water-ethylene glycol mix
• - Incubate 5 min to 1 hr to be determined
• Spritz 3 Wash excess probe away

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Implementation Issues

• Are prototypes to be tested? Manual method works
• What are the potential failure conditions?
• Clogging
• Wind blows spray away or into optics
• Electronic system fails
• What are the major schedule issues?
• Need person for this work 2d/wk, 4 wks
• Manual testing with chemistry/biology 20d
• System needs to be designed for rover
  electronics, mechanical, space on rover

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Cartoon of spritz system
Pumps
Rock
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Fluorescent probes
Dye Absorption max (nm) Emission max
(nm) Enhancement on binding DNA probes SYTO
9 470 530 SYTO BC 480 500 DRAQ56
506 700 Protein probes Fluorescamine 380 464
OPA/2ME 334 455 NDA/CN 419 493 C
BQCA/CN 465 560 SYPRO Orange 470 570
SYPRO Red 550 630 Lipid
probes DPH 353 449 Nile Red 559 637
DiI(7) 750 780 Carbohydrate
probe Calcofluor White 360 480