Analysis of biological targets using a biochip comprising a fluorescent marker

1. Analytical support comprising a plurality of oligonucleotides fixed on this support, wherein each of said oligonucleotides is marked by a fluorescent compound such that the fluorescence of an oligonucleotide marked by this compound is attenuated after hybridization of this marked oligonucleotide with a complementary oligonucleotide, wherein said fluorescent compound is selected from the group consisting of flavin and deazaflavin.

2. Support according to claim 1 , wherein the attenuation of fluorescence is a variation of fluorescence intensity, a variation of the time constant of the fluorescence, or a shift in wavelength of the fluorescence.

3. Analytical support according to claim 2 , wherein the fluorescent compound presents a fluorescence intensity before hybridization.

4. Support according to claim 3 , wherein the attenuation represents 30 to 99% of the fluorescence intensity before hybridization.

5. Support according to claim 1 , wherein the fluorescent compound is flavin.

6. Support according to claim 1 , wherein the fluorescent compound is deazaflavin.

7. Support according to claim 1 , wherein the oligonucleotide is marked by a group of formula —(CH 2 ) n —R 1 in which n is an integer from 2 to 8 and R 1 represents a group corresponding to one of the following formulas:

8. Support according to claim 4 , wherein the oligonucleotide is marked by a group of formula —(CH 2 ) n -R 1 in which n is an integer from 2 to 8 and R 1 represents a group corresponding to one of the formulas II and III

9. Support according to claim 7 , wherein n is 6.

10. Support according to claim 8 , wherein n is 6.

11. Control method for an analytical support comprising a plurality of oligonucleotides fixed on that support, wherein the fixed oligonucleotides are oligonucleotides marked by a fluorescent compound and further wherein the quantity of oligonucleotides fixed on the support is localized and determined by measurement of the fluorescence of the fluorescent compound,

wherein the fluorescent compound is chosen from the group consisting of flavin and deazaflavin.

12. Method for analysis of biological targets by putting these targets in contact with an analytical support comprising a plurality of oligonucleotides and determination of a hybridization between targets and the oligonucleotides of the support, wherein an analytical support as claimed in claim 1 is used, and further wherein the oligonucleotides of the support which have given rise to a hybridization are determined by measurement of the fluorescence corresponding to each oligonucleotide of the support before and after putting the support in contact with the targets.

13. Method according to claim 12 , wherein the targets are also marked by a second fluorescent compound whose emission wavelength is different from that of the fluorescent compound of the oligonucleotides, or first fluorescent compound, and the oligonucleotides that have given rise to a variation of fluorescence are controlled by measurement of the fluorescence of this second compound.

14. Method according to claim 12 , wherein the fluorescent compound of the oligonucleotides of the support, or first fluorescent compound, is chosen from the group consisting of flavin and deazaflavin, and the second fluorescent compound is chosen from the group consisting of stable fluorophores shifted towards the red with respect to flavin.

15. Method as claimed in claim 12 wherein the fluorescence intensity of the first compound is measured by spectrometry.

16. Method according to claim 13 , wherein the second fluorescent compound is CY 3 whose excitation wavelength is 543.5 nanometers and whose emission wavelength is 580 nanometers.

17. Method according to claim 16 , wherein the presence of this second compound is determined with a scanner using a HeNe laser.