If the entire pellet is not analyzed, you must ensure that 0.5 mL of packed pellet is processed per Leighton tube to maximize the sample examined. Again, measure the resuspended volume by pipetting or compare with centrifuge tube standards similar to pellet standards.
The easiest way is to divide the total resuspended volume by the packed pellet volume. This calculates the volume of concentrate that is equivalent to a mL of packed pellet; multiplying by 0.5 mL calculates the volume of concentrate equal to 0.5 mL of packed pellet. This is the transfer volume per Leighton tube.
Examples:10 L filtered 2.74 mL packed pellet 4 IMS reactions | 10 L filtered 5.0 mL packed pellet 4 IMS reactions | |
---|---|---|
Estimated Resuspended Volume | 27 mL | 50 mL |
Measured Total Resuspened Concentrate | 30 mL | 55 mL |
Number of IMS Reactions Processed | 4 | 4 |
Volume Transferred to each Leighton Tube | 30 mL/2.7 mL x 0.5 mL = 5.6 mL | 55 mL/5 mL x 0.5 mL = 5.5 mL |
Total Volume Transferred | 5.6 mL x 4 = 22.4 mL | 5.5 mL x 4 = 22 mL |
Volume Examined | 22.4 mL/30 mL x 10 L = 7.4 L | 22 mL/55 mL x 10 L = 4 L |