The information below provides detailed support on sample-related issues. If you are looking for trouble shooting information (e.g. because you are unhappy with your results), please go to our trouble shooting area. Should you not find the answer to your question/problem here, please contact us and we will do our best to help.

What types of sample to send...

From our products page, you will see that we can accept various types of sample according to the option being requested. However, for DNA sequencing we really need either a good quality mini- or maxi-prep or a cleaned up PCR product.

Plasmids must be of high quality if you are to achieve decent results. Almost any commercial kit will generate such DNA if used properly. If you intend not using a kit, do not send us plasmid DNA from quick and dirty "boiling" methods or the like - they will not work.Instead, use a standard alkaline lysis method and clean up the resulting DNA by a deproteinating step (e.g. phenol/chlorofom or equivalent) and ethanol precipitation. Preferably, just use a commercial kit! They are not expensive. Alternatively, allow us to do your preps for you (check out our products page).

PCR products must be clean single band and must be purified to remove unwanted PCR products, excess PCR primers and remaining dNTPs from the PCR reaction. Please take a look at our detailed page regarding direct sequencing of PCR products. Failure to clean up the PCR product is very likely to result in a messy sequence for reasons which should be obvious, but if they are not, check out our trouble shooting section. To clean up your PCR products, you may need to gel purify it. Alternatively, you may be able to just remove excess primers and dNTPs without performing gel purification. We do not recommend a specific kit for either gel or non-gel purification of PCR products. As with plasmids, just about any commercial clean-up kit will work well if used properly. We can recommend from personal experience using the Exo-SAP method. This is quick and simple (and cheap) and we have more information about it in our trouble shooting section.

How much sample to send...

Information on the amount of sample to send for each of our contract research DNA sequencing options is given on the appropriate product page. However, since you are here.... For our standard sequencing options, we do ask for twice the amount of DNA template as required so that, should it be needed, we can perform repeats without you having to send more template. For regular plasmids, this means 600ng in 30µl per reaction being requested. Please do send this amount of DNA, since it makes it much quicker and easier for us to perform any repeats that may be needed. For primers, we specify a minimum volume of 10 µl to avoid problems with evaporation. Primers should be supplied at 3.2 µM (this is the same as 3.2 picomoles per microlitre) for regular samples (plasmids and PCR products). For large templates (e.g. BACS, PACS, etc), they should be supplied at 7.5µM. The exception to the above is our 96 well plate sequencing option, where we specify that customers must provide the amount for one reaction in each well of the plate. For regular plasmids, this means 250-300 ng of plasmid in 15 µl combined with 1 µl of primer from a stock that is at 3.2 micromolar.

How to package the sample(s)..

Please ensure that samples are clearly labeled so that we can identify them. If we cannot read what it says on the side of your tube, we cannot process it! Please also ensure that your samples are well protected and packaged to meet Post-Office or courier regulations. At a bare minimum, you should use a "Jiffy" style padded envelope for DNA samples in plastic tubes. The postal service is not kind to regular envelopes and we routinely receive envelopes with crushed tubes in them, tears in them and tubes missing, or indeed not receive them at all! We also find that franking machines in institutions can be a common cause of tube crushing. For E. coli pellets, packing in dry ice within a polystyrene insulated container is the only packaging method we can accept for items sent by courier.

Sending by courier or by Royal Mail...

For DNA samples or agar plates, normal first class post should be sufficent. However, it is becoming increasingly evident that first class post does not always mean "next day post". In fact, it can sometimes take up to a week for samples to arrive. We would therefore recommend that customers who have deadlines to meet send their samples by a guaranteed next day delivery service . Whichever method you choose for your samples, you will be responsible for paying all postage / carriage charges. If sending by Royal Mail, please be aware that the new letter sizes / thicknesses and tarifs, could mean that you are affixing insufficient postage to your package. This will cause a delay in use receiving the package and usually results in us being charged for receiving the package. We will pass this charge onto the customer. E. coli pellets being sent by customers who cannot hand deliver them to us must be sent by courier (on dry ice as detailed above).

Getting us to keep templates / primers...

We will routinely keep for a couple of weeks any extra material that we do not use. This allows customers to contact us and ask for repeats of failed reactions, etc. Due to space constraints, we can only keep such samples for this sort of time period. Should customers wish us to keep their samples for longer, they must tell us this when submitting the samples. The two main reasons why customers ask us to keep samples are (1) that they want us to sequence one end of a construct and then, depending on the result, either sequence the other end or not and (2) that they want us to keep primers for future use. Within reason, we are happy to keep any sample that we are asked to keep so that it is available for future use. However, we cannot keep every sample and it is the responsibility of the customer to tell us that they want us to keep the sample(s) when they submit those sample(s) for sequencing.

Getting samples back again...

We are more than happy to return unused sample to customers. However, we do charge reasonable postage and packing expenses for doing this and there is no guarantee that the sample will arrive back intact or even at all (unless the customer is prepared to pay extra for a guaranteed service). For this reason, we would strongly urge customers to keep back some of the sample that they send to us, thereby avoiding the need to have material returned.