You could select the following forms for Oligo synthesis and DNA Sequencing servies:
Please click on the following order form in pdf and word format. We do recommend 50nmol Scale, Desalted.
Oligo synthesis form in PDF format (Please print fill in and fax it back to us 510-625-8419), Oligo synthesis form in Word format (Just fill in the form save it as an attachment and email it back to us.
Or you could just fiill up the online form, click here DNA sequencing online form
OLIGO ORDER FORM HELP|
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How Pure is Pure Enough?
In general, the purity required for a specific application depends on the potential problems from the presence of failure sequences (n-1,n-2,....oligomers). For some applications, desalted oligos are satisfactory. For others, only HPLC or PAGE may yield oligos of sufficient purity. Yields will also vary according to the selected purification method.
Desalting removes residual by-products from
the synthesis, cleavage
and deprotecion procedure. Bionexus desalts every oligo.
For a higher level of purity all shorter non-extended synthesis
can be removed. We recommend RP-HPLC for oligos shorter than 45
bases. The full-length product is 95-99% pure.
With the excellent resolution of PAGE for oligos longer than 45 bases. The full-length product is 95-99% pure. Recommended applications: gene synthesis, 32P-labelling.
Antisense / NMR grade:
If you want to use antisense oligos in cell culture, it is important
to take care of the salts within the oligo sample. Our antisense
oligos are precipitated and carefully dialyzed after a reversed
The scale of synthesis is the amount of 3' base that we start the synthesis with. It is NOT the expected final yield. The yield depends on the size of the oligonucleotide, the coupling efficiency(98-99%), and the base composition.
Theoretically the yield of the unpurified full length product is calculated using the formula 0.98n or 0.99n.
|MINIMUM OD260 YIELD:|
Based on an unpurified 20-mer oligonucleotide:
160 bases on the 0.2 umol scale. 60 bases on the 40 nmol scale.
We do not increase our per-base charge to make longer oligonucleotides.
Bionexus uses industry standard beta-cyanoethyl phosphoramidite
chemistry. This chemistry has been proven
to be robust and to yield high quality oligos.
We monitor trityl yields and final synthesis yields. In addition,
we monitor the overall synthesis quality of each oligonucleotide
by gel electrophoresis and a digital gel image is supplied.
Bionexus /ABP custom oligonucleotides carry
an unconditional guarantee and are backed
by the highest quality technical support.
The label on every tube indicates the sequence, sequence number,
nmol yield, oligo name, purification method and the modifications.
We do not charge extra for the yield determination.
|SHIPPING / DELIVERY TIMES:|
The oligonucleotides are shipped as lyophilized powder
at room temperature in a clear 1.5 ml microcentrifuge tube. They
have been deprotected in ammonia and desalted over Sephadex
G-25. The Sephadex removes any excess ammonia, protection
groups and very short oligonucleotide truncation products (5-mer
95% of our oligos are shipped out at the next day after receipt
of your order (they have to pass the quality control) No shipment
fee for A-priority.
|CALCULATIONS / CONVERSION FACTORS:|
Definition of OD260
One OD unit of DNA is the amount of DNA that gives an absorbance reading of 1.0 at 260 nm for a sample dissolved in 1.0 ml total volume of ddH2O which is read in 1 cm quartz cuvette. (OD = "Optical Density"). For oligonucleotides, 1 OD is approximately 33 ug of DNA.
Melting Temperature (Tm) Estimation for Oligonucleotides.
The melting temperature (Tm value) of an oligonucleotide is dependent upon the length of the sequence, the G+C content of the sequence, and the type and concentrations of cation present, particularly sodium ion, Na+. A variety of formulas have been used for predicting Tm values. These tend to be fairly accurate for long DNA sequences, but are less accurate for oligonucleotides. The following formula is recommended for oligonucleotides ranging in length from 20 to 100 residues, and [Na+] concentrations ranging from 0.01 M to 1.0 M:
Tm (in degrees C) = 81.5 + 0.41(G%+C%) + 16.6 log[Na+] - 500/length
For example, for a 40-mer with a 55% G+C content in a 0.1 M NaCl solution:
Tm = 81.5 + 0.41(55) + 16.6 log[0.1] - 500/40
= 81.5 + 22.5 + 16.6(-1.0) - 12.5
= 74.9 degrees C
Annealing Temperature for PCR.
Calculate the melting temperature as above and subtract 5 to 10 degrees. If the two oligonucleotides have different melting temperatures, do NOT average the numbers. Use the lower number so that both of the oligonucleotides can anneal.
Molecular Weight = (A x 312.2)+(G x 328.2)+(C x 288.2)+(T x 303.2)-61 where A,C,G,T are # of A's, C's, G's and T's in an oligo.
Conversion Factor (Approximate Values)
OD units to ug Equivalence
1 OD260 unit of an oligo ~ 33 ug
1 OD260 unit of SS RNA = 40 ug
1 OD260 unit of dS DNA = 50 ug
OD Units to Nanomoles Equivalence
nmoles of oligo = 100 x OD/length of oligo
DNA Molar Conversions
1 ug of 1,000bp DNA = 1.62 pmol (3.24 pmoles of ends)
1 ug of pBR322 DNA = 0.36 pmol DNA
1 pmol of 1,000bp DNA = 0.62 ug
1 pmol of pBR322 DNA = 2.78 ug
We can economically supply a large number of aliquots of a sample, or sets of samples. This may help several labs share the same set of oligos.
We can produce entire genes of up to 15'000 base pairs in length to your custom specifications.
To minimize your carry-over contamination in a polymerase chain reaction
we deliver ready to use PCR-buffers (also prefilled in your PCR tubes).