What are some other technical tips for resolving dark backgrounds?
Remember to change from blue caps (vortexing) to white caps (centrifuging). This will avoid any sample contamination of the filtrate. Check to make sure your filtrate volume is correct. Pipet to the first mark from the bottom of the Transfer Pipet (0.5 mL). Remember to repeat the second Wash Step. Add second six drops of wash solution to the membrane. Repeat testing using a ¼ sample volume. Dark membrane background problems may be due to interfering substances reduced with ¼ sample. Test sensitivity is not affected by reduction in sample volume.
