Call rates and Log R Dev for Infinium BeadChips are calculated using signal intensities that rely on effective staining across the BeadChip. Glass back plates are a key component of the flow-through chambers that control the flow of XStain reagents over Infinium BeadChips. Careful cleaning and handling of glass back plates is critical for the quality of the XStain procedure. Follow these updated recommendations for the best results.

General best practices

• Inspect glass back plates prior to every use. If there is any damage to the reagent reservoir or surface that faces the BeadChip, replace the glass back plate.
• Clean glass back plates according to the following schedule and protocols:
  • Before the first use: Cleaning the glass back plates after every use
  • After every use: Cleaning the glass back plates after every use
  • After every 7 uses: Bleach cleaning the glass back plates

Best pratices updates

• Use a plastic test tube rack (Cole-Parmer – Item # EW-06739-17) for cleaning, bleaching, and storage of glass back plates. Place glass back plates diagonally in the racks to minimize contact between the glass and to prevent damage.
• Immediately after the XStain procedure, disassemble flow-through chambers and place the glass back plates diagonally in a plastic test tube rack submerged in a container of diH2O to prevent XStain reagents from drying on the glass back plates. Keep glass back plates submerged in diH20 until ready to proceed to Cleaning the glass back plates after every use.
• Consider your method for tracking the number of uses for each glass back plate, such as labeling the storage racks. CAUTION: if you write on the glass with marker, it will bleed into the array area during XStain and negatively affect the staining.

Cleaning glass back plates after every use 

1. Prepare a 1% Alconox solution using 2.5 g Alconox powder per 250 ml diH2O.
2. Place the plastic test tube rack with glass back plates in a container filled with 1% Alconox.
3. Wipe each glass back plate with a Kimwipe and return to rack in Alconox.
4. Remove the rack from the 1% Alconox solution and thoroughly rinse the glass back plates with diH2O.
5. Allow the glass back plates to dry in the plastic rack.
6. After the glass back plates are clean and dry, wipe them with a Kimwipe soaked with 70% EtOH.
7. Store glass back plates diagonally in a plastic test tube rack, in a dust-free area.
8. Before use, remove any dust or lint on the glass back plates using a can of compressed air or a laboratory air gun.

Bleaching cleaning the glass back plates 

WARNING: Do not perform this cleaning protocol in the BeadChip processing lab. Excessive bleach fumes can degrade the fluorescent dyes used in the Infinium assay. Use the proper precautions when handling bleach, including wearing a lab coat, safety goggles, and gloves. Perform the following steps in a fume hood.

1. Make a 10% bleach solution.
2. Place a plastic test tube rack with the glass back plates in a container with enough 10% bleach to cover the glass back plates. Soak for 1 hour.
3. Transfer the plastic test tube rack with the glass back plates to a container with diH20.
4. Dip the rack up and down 20 times, being careful not to damage the glass back plates.
5. Remove the rack with the glass back plates and rinse with diH20.
6. Dispose of the diH20 and then return the rack to the container filled with fresh diH20.
7. Dip the rack containing the glass back plates up and down 20 times. Soak for 5 min.
8. Repeat steps 5-7 four times.
9. Dry the glass back plates in the plastic test tube rack.
10. After the glass back plates are clean and dry, wipe them with a Kimwipe soaked with 70% EtOH.
11. Store glass back plates diagonally in a plastic test tube rack, in a dust-free area.
12. Before use, remove any dust or lint on the glass back plates using a can of compressed air or a laboratory air gun.

For additional information, refer to the Infinium Assay Lab Setup and Procedures Guide.