BioMicroCenter:Multiplex: Difference between revisions

From OpenWetWare
Jump to navigationJump to search
Line 7: Line 7:
[[IMAGE:BioMicroCenter_Barcode.png|1200px]]
[[IMAGE:BioMicroCenter_Barcode.png|1200px]]


5' Barcodes have the advantage that they are read as part of a single read. The disadvantage of the barcode is they require two primers to make (both halves of the Y-shaped adapter) and, due to the way Illumina finds clusters, you must use a large number of barcodes in each run (16+). In addition, because they are part of the ligation event, care must be taken that the barcode is not introducing biases in library construction. 3' Barcodes are more flexible, being added during the PCR step, and can have a number of different compositions and can be run in any number. The do require a second read to sequence which can add extra cost to the flowcell.
The main advantage of 5' barcodes is the fact that they are read as the first part of read 1, eliminating the need for a separate barcode reprime. A disadvantage is that sample prep will require two different primers (both halves of the Y-shaped adapter). Also, because the cluster-calling algorithms require a balanced base composition over the first few nucleotides, you must use a large number of barcodes in each run (16+). In addition, because the barcodes are present during the ligation reaction, care must be taken to prevent them from introducing biases in library construction. <br> 3' Barcodes are more flexible as they are added during the PCR step, can have a number of different compositions, and can be run in any number. They do require a second read to sequence which can add extra cost to the flowcell.


== MULTIPLEXING AT BIOMICRO ==
== MULTIPLEXING AT BIOMICRO ==

Revision as of 11:48, 28 September 2011

HOME -- SEQUENCING -- LIBRARY PREP -- HIGH-THROUGHPUT -- COMPUTING -- OTHER TECHNOLOGY

MULTIPLEXING

Multiplexing methods allow for running multiple samples in a single Illumina lane. There are multiple strategies for multiplexing Illumina samples but they can generally be broken down into two classes: 5' barcodes and 3' barcodes.

The main advantage of 5' barcodes is the fact that they are read as the first part of read 1, eliminating the need for a separate barcode reprime. A disadvantage is that sample prep will require two different primers (both halves of the Y-shaped adapter). Also, because the cluster-calling algorithms require a balanced base composition over the first few nucleotides, you must use a large number of barcodes in each run (16+). In addition, because the barcodes are present during the ligation reaction, care must be taken to prevent them from introducing biases in library construction.
3' Barcodes are more flexible as they are added during the PCR step, can have a number of different compositions, and can be run in any number. They do require a second read to sequence which can add extra cost to the flowcell.

MULTIPLEXING AT BIOMICRO

The BioMicro Center uses 3' barcoding for our sample preparation. Barcoding is available for *FREE* as part of our full Illumina sample preparation service and is done during the amplification step. The barcodes we use are 6nt in length and are differentiated by at least 2nt from any other barcode. We currently have a stock of 40 barcodes and have designs available for over 100.

Reading BMC barcodes requires a re-prime of the sequencer and there are some additional charges for multiplexing samples. A full list of our prices is here.