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Department of Biochemistry


The Department has conducted a comprehensive COVID-19 risk assessment process and has introduced a number of new measures to ensure the safety of our staff. In order to accommodate these new measures, our facilities will be operating revised services for the foreseeable future. Details of current arrangements and available services can be found here.

 Sample Requirements

DNA submitted to the facility needs to be very pure, much purer for instance than for manual sequencing. It is for this reason that we recommend that DNA should be prepared using a commercial kit such as Qiagen. Traditional methods, ie. alkaline lysis, can work if care is taken.

  • Reda_smallPlasmid DNA should be supplied at a concentration of 100ng/µl and a volume of 3 µl per reaction* in water 
  • Cosmid DNA should be supplied at a concentration of 150ng/µl and a volume of 3 µl per reaction* in water 
  • PCR fragments should be supplied at a concentration of 20ng per 100 base pairs (see table below) and a volume of 3 µl per reaction* in water 

*Minimum 10 µl volume required to allow for evaporation or any other potential loss and any repeat reactions if necessary

PCR Product
Size Concentration
100-200bp 1-3 ng/ul
200-500 bp 3-10 ng/ul
500-1,000 bp 5-20 ng/ul
1,000-2,000 bp 10-40 ng/ul
>2,000 bp 40-100 ng/ul

Any non-standard primers submitted should be at a concentration of 10pm/µl (10µM) in water. We use 3µl of primer solution per sequencing reaction, but please give us a minimum volume of 10µl to allow for evaporation or any other potential loss and any repeat reactions if necessary.

We need the correct amount of DNA as indicated above, not too little but also not too concentrated since we do not have the time to make further dilutions due to the large numbers of samples we receive. Most experienced sequencers will be able to make an accurate assessment of DNA quantity but some may have difficulty. One method is to use a Nanodrop. This can give consistent, accurate results and automatically provides abs. 260/280 ratio (which for best results should be around 1.8).

N.B. DNA for sequencing should always be supplied in water only and not TE or Tris buffer. Also please submit samples in tubes no smaller than 0.5ml to avoid handling problems.

Samples and completed DNA sequencing request forms can be dropped off in the basket provided in the Biochemistry reception (Sanger Building) or posted to the facility at the following address:

DNA Sequencing Facility
Department of Biochemistry
University of Cambridge
80 Tennis Court Road
Old Addenbrookes Site

Sequencing requests from anywhere other than Biochemistry must be accompanied by a printed purchase order.

Results are sent via email so please ensure that the mailbox size is sufficient.