Instruction manual

16 World Precision Instruments

Solenoid Input Selection Switch. When the pipette is full, set the Solenoid Input

Selection Switch to Hold.

7. Set the Duration switch to Gated. Hold down the foot switch to eject ﬂ uid from the

micropipette into the oil-ﬁ lled dish.

8. Record the amount of time it takes in seconds for the meniscus in the micropipette

to travel from one 1mm mark to the next. It should take between 20 and 30

seconds for each injection. You may need to adjust the eject pressure to achieve this

time frame.

9. Repeat steps 7–8 three times

10. Average the three trials to ﬁ nd the average time it takes to inject a 1mm column of

ﬂ uid.

11. Calculate the volume of a 1mm segment of your micropipette using the volume

formula for a cylinder:

r= radius of the pipette = ID/2

h= length of the pipette = 1000μm

r

h=ID

1000/4 = 785 * r

• Thin wall 1 mm glass has a nominal 0.750μm ID, and a 1mm length contains

0.4418μL of ﬂ uid (442nL).

• Standard wall 1B100 glass has a 0.580μm ID, and a 1mm length holds

0.2641μL of ﬂ uid (264 nL).

Both those ID’s have a ±100μm tolerance, and that ID dimension is vital to making a

correct injection of 1nL.

12. Divide the average found in step 10 by the calculated volume in nL of a 1mm length

of your pipette found in step 11. This establishes the time in milliseconds that it

takes to inject a known volume. From there you can calculate how many nanoliters

can be injected per second and how many milliseconds it takes to inject a single

nanoliter of ﬂ uid.