HAMILTON MICROLAB® STAR

Sequence Controlled Loops

Sequence Controlled Loops

Loop continuously until current position marker of controlling sequence goes past end position marker and is therefore set to zero

Main use to control loops when you don’t know the length of the controlling sequence in advance i.e Number of positions in sequence used

controlled by a user input "How many samples today?"

Sequence generated based on worklist

How to set up a Seq controlled loop

Select sequences that will be used in asp/dis steps in loop

If using fresh tips for each asp/dis step select tip sequence as well Always set reset to never for tip sequence or tip

seq will be reset after loop and method will try to pick up tips from positions that have already been used

Why include tip sequence

Enables the seq controlled loop to handle the situation where the last loop has less than 8 samples (on 8 channel instrument) On last loop all sequences effectively set to

same length as controlling seq If controlling seq only has 4 positions left, tip

sequence effectively set to have only 4 positions and 4 tips will be picked up

When not to include tip sequence

Do not include tip sequence in list of sequences to iterate over and adjust if keeping same set of tips on for loop (i.e dispensing buffer) Can lead to the incorrect number of

channels being used (see advanced user section for more details)

Examples

Transfer samples from one plate to another using new tips each time Key Features

Include tip seq in seq controlled loop Increment sequence on aspirate and

dispense Demo method

seq_controlled_loops_demo_fresh_tips

Examples

Adding buffer to plate using one set of tips Key Features

DO NOT include tip seq in seq controlled loop

No sequence increment on asp in order to reuse buffer reservoir

Demo method seq_controlled_loops_demo_one_set_tips

HAMILTON MICROLAB® STAR

Advanced Users section

How do seq controlled loops work

Start of loop Checks condition for running loop is still valid

i.e current position marker of controlling seq not zero

Sets Max property of each seq included in loop to the Max value of the SHORTEST sequence

Max is maximum number of positions available in seq

Max = (End – current) +1

How do seq controlled loops work

During loop Perform asp/dis step using Max number of

positions (if max>number of channels, uses number of channels positions)

Sequences incremented as per settings in asp/dis steps (Max is then recalculated at start of next loop based on new current position marker)

Example – transfer samples (fresh tips)

Before loop (Current/end/max)

Start of loop 1

(Current/end/max)

Source Seq (controlling)

1/20/20 1/20/20

Destination Seq

1/96/96 1/96/20

Tip Seq 1/192/192 1/192/20

Example - What happens at the start of the loop

8 Channel instrument

How do seq controlled loops work

loop 1

Start (Cur/end)

loop 1

Start

(Max)

loop 2

Start (Cur/end)

loop 2 Start (Max)

loop 3 Start (Cur/end)

loop 3 Start (Max)

loop 4 start

(Cur/end)

Source Seq (controlling)

1/20 20 9/20 12 17/20 4 0/20

Destination Seq

1/96 20 9/96 12 17/96 4 21/96

Tip Seq 1/192 20 9/192 12 17/192 4 21/96

Source, destination and tip seq incremented during asp/dis step in loop

Example - What happens during the loop

How do seq controlled loops work

In loop 3, as Max is set to 4, only 4 tips are picked up and 4 positions used in source and destination sequences

At start of loop 4, condition to run loop no longer valid as current position marker of controlling sequence equals Zero. Loop broken and loop 4 does not execute

How do seq controlled loops work

What happens if you include tip sequence in seq controlled loop but use same set of tips for loop. Conditions that will cause a pipetting issue

Length of pipetting sequences must trigger a second loop

Tip sequence must be incremented Number of tips in tip sequence, (End-

current)+1, must between one and two times the number of channels used in the pipetting step.

Example – one set tips (tips seq included in seq controled loop)

loop 1

Start (Cur/end)

loop 1

Start

(Max)

loop 2

Start (Cur/end)

loop 2 Start (Max)

Source Seq (i.e buffer)

1/8 8 1/8 1

Destination Seq (controlling)

1/24 8 9/24 1

Tip Seq 1/9 8 9/9 1

Example – 8 channel instrument

Destination seq and tip seq incremented during asp/dis step in loop

• As tip seq included in the loop, Max of all sequences set to Max of shortest sequence at start of loop 2• As max is now 1, a single channel will be used to complete seq

controlled loop

Examples – Using NTRs

When using NTR’s and GB NTR DirectUse library, putting tip sequence into loop doesn’t work

Example - transfer samples using new tips each time Key Features

At start of loop get Max of controlling seq (SeqLib)

Create channel pattern based on Max using GB Create_Channel_Pattern library

Use gettips_channels step of NTR DirectUse library to pick up tips using channel pattern created

Examples – Using NTRs

Example - transfer samples using new tips each time Demo method

seq_controlled_loops_NTR_fresh_tips Example – Adding buffer to plate using same set of

tips NTRDirectUse gettips_channels step outside of

loop and channel pattern based on number of tips required

Demo method seq_controlled_loops_NTR_one_set_tips