Instrumental Analysis

Instrumental Analysis

1. Write Bragg’s Law

2.Write name of the two metals we commonly use as anode in home X-ray source.

3. How many primers are required during PCR based DNA sequencing using Sanger’s method?

One b. Zero c. Two d.Four

4. During the manual method of DNA sequencing the primer is labelled by:

Adding all four dNTPs in regular amount and DNA polymerase
Adding all four dNTPs in regular amount of which one is radioactively labelled and DNA polymerase
Adding all four dNTPs in limiting amount of which one is radioactively labelled and DNA polymerase
Adding all four dNTPs in limiting amount and DNA polymerase

5. High throughput DNA sequencing using Sanger’s method was possible due to

improvement in the:

Labelling and detection methodb. Fragment separation technique

c. DNA polymerase used and resulting strategies for generation of fragments

All of the above

6. In the ABI Prism 310 machine the capillary is filled with:

Polyacrylamide gel solution b. A liquid polymer

c. Agarose gel solution d. Sephadex beads

7. The novelties of the Solexa method of DNA sequencing are:

(a)Generation of millions of clusters of different DNA templates on a tiny solid surface

(b)Use of reversibly 3’ blocked deoxynucleotides

(c)Use of fluorescence labelled dideoxynucleotides (d) a and b both

8. A cation-exchanger chromatography column can be done at any pH?  True  False

9. At a constant pH, all unabsorbed fractions of a cation-exchanger will bind to an anion-exchanger.  True  False

10. Re-chromatography always yields better purification.  True  False

11. A gel filtration chromatography followed by a cation or anion-exchanger chromatography is a better sequence for purification of a protein than the reverse order.

 True  False

12. Resolution power of a gel filtration column is significant near or within its

 Void volume Fractionation range  Desalting zone

13. Can a lectin (carbohydrate binding protein) be separated using a Sephadex matrix (cross inked dextran) based on its molecular weight?  Yes  No

14.Binding of a material to hydroxyapatite column involves:

 Adsorption phenomenon  Absorption phenomenon

 Non-specific binding  Specific binding.

15. In reverse-phase HPLC, the column matrix is:

 positively charged negatively charged  Hydrophobic  Hydrophilic.

16. Is there any restriction on the volume of sample to be applied to a cation or anion exchanger column?  Yes  No

17. For the detection of DNA fragmentation it is preferred to use

a)EI b)MALDI c)ESI d)APCI

18. How many peaks would you expect in the mass spectrum of 1-bromobutane and

what should be their intensity?

(a)3, 1:1:1 (b) 2, 2:1 (c) 2, 1:1 (d) 2, 3:1

19. If the observed mass of a biopolymer are m/z 671.584 & 638.078, then the actual

mass is

a)12730.968 b) 12741.096 c)12731.096 d)12740.096

20. Predict the double bond equivalent (D.B.E) of the molecule whose molecular formula is C11H16.

a) 5 b) 3 c) 4 d) 6

21. Predict the nature of the compound whose molecular weight is 121.

a)Ester b) Alcohol c) Amide d)Acid

What should be the most abundant peak in the mass spectrum of 1-(4-methylphenyl)-ethanol?
126b. 121 c. 119 d. 110

Define Precision frequency. What is the relationship between Precision frequency and Static Magnetic Field strength (B0)?

What is Scalar coupling? Explain its effect on the observed NMR spectrum.

25. Circular dichroism is the difference in the absorption

(a) of incident and diffracted light (b) of incident and absorbed light

26. Circular dichroic spectral pattern is generally expressed in terms of

(a)wavelength versus optical density

(b)wavelength versus molar ellipticity

(c)wavelength versus refractive index

(d)wavelength versus absorbance

27. The CD spectrum of a DNA polynucleotide has a long wavelength negative band (inthe

280-300 nm) followed by positive band around 250 nm. The structure can be most likely

(a)alpha helix (b) left handed Z-form (c) beta sheet (d) right handed B-form

28. An alpha helical conformation of a protein is characterized in CD by the

(a)double minima at 222 and 208 bands

(b)negative and an equally positive band at 222 nm

(c)positive CD bands in the 200-230 nm region

(d)a negative band at 205 nm

29. In fluorescence spectroscopy external energy is supplied to the sample by means of

(a)UV/Vis light (b) Radio active decay (c)Fluorescent light (d)None of the above

30. In fluorescence spectroscopy the detector is placed at 90o to the incident light to get

better signal-to-noise ratio, when compared to the 180° geometry

(a)avoid external light

(b)to avoid reflection

(d)to avoid transmitted excitation light and stray light

31. Fluorescence polarization (anisotropy) gives information about

(a)shape, size and flexibility of the molecules

(b)molecular weight of the molecules

(d) concentration of the molecules in the solution

32. Fluorescence Resonance Energy Transfer only occurs when the two fluorophores are more or less within about

(a)anywhere beyond 1000 Ǻ (>0.1μm) (b) 200-1000 Ǻ (0.02-0.1μm)

33. The fluorescence spectrum of a protein has an emission maximum at 348 nm when excited at 280 nm. The fluorescence may be most likely from the

(a) phenylalanines (b) tyrosines (c) tryptophans (d) none of the above

34. Intracellular Ca2+ using Confocal Microscope can be measured by loading cells with which of the following dyes?

(a)Fluo 3AM (b) Fluo 3 (c) Rhodamine (d)Alexa Fluor 488

35. The amount of “out of focus light rays” into the detector of a confocal microscope will be increased if

(a)Pinhole is decreased (b)Pinhole is increased

36. The primary benefit of the confocal microscope over the conventional wide field microscope is

(a)The ability to control the depth of the field by confocal microscope

(b)Image is more clear in confocal microscope.

(c)The digitization is more easier by confocal microscope

(d)None of the above.

37. Name the suitable dye (s) for staining nucleus.

(a)Alexa Fluor 633 (b) DAPI (c) Propidium iodide (d) Both b and c

38. Confocal eliminates “out of focus information” by using which one of the following devices?

(a)Beam splitter (b) Pinhole (c) Mirror (d) Objective

39. The primary limiting factor for resolution in a light microscope is the:

a) quality of the lensesb) index of refractionc) wavelength of light

40.Which of the following is NOT true of electron microscopy (EM):

a) EM can be used to examine the movement of flagella

b) EM uses heavy metals as stains

c) Electrons replace light in the electron microscope

41. When biologists wish to study the internal ultra-structure of cells, they most likely would use:

a)a transmission electronic microscope

b)a light microscope

c)a scanning electron microscope

42. In its optical design, the transmission electron microscope is most like a(n):

a)atomic force microscope

b)compound light microscope

c)scanning electron microscope

43. Which instrument gives the most "3-dimensional-like" image?

a)Compound light microscope

b)Transmission electron microscope

c)Scanning electron microscope

44. How does the scanning electron microscope differ from the transmission electron microscope? It:

a)uses electromagnetic lenses

b)operates with a vacuum

c)maps images rather than optically projecting them

45. Define the role of isotype-matched control antibody in immunofluorescence staining.

46. Explain the principle of annexin V-FITC staining for measurement of apoptosis.

47. How can you distinguish apoptosis from necrosis in flow cytometry?

48. You would like to amplify a 1kb fragment using the Polymerase Chain Reaction. What is the expected number of copies of the fragment at the end of 20 cycles if

(i) two primers are used ______

(ii) one primer is used in the PCR ______

49. Specificity of a PCR can be increased using the technique ______PCR

50. Advantage of Sybr Green over ethidium bromide in real time PCR id due to one or more

of the following:

(a) Sybr Green and not ethidium bromide intercalates into double stranded DNA

(b) Sybr Green fluoresces with higher intensity than ethidium bromide when boundto

double stranded DNA

to single stranded DNA

(d) Sybr Green fluoresces with higher intensity than ethidium bromide whenbound to

double stranded and single stranded DNA