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Published byElfreda Stewart Modified over 9 years ago
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1 Purifying DNA & RNA Source Amounts & Purity Damage or Loss
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2 Bind DNA Cells Pure DNA Extract Remove junk
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3 DNA, RNA Solution Denatured Protein Phenol Cell Extract ShakeSpin 1. Remove high MW junk
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4 (to 70%) SPIN (fast) Add and salt 2. Remove low MW junk and concentrate
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5 BIND + SALT (aided by alcohol) ELUTE - NO SALT (just add water) Or Bind DNA
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6 EXTRACT IN High Salt SILICA PARTICLES WATER DNA High Salt Wash
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7 Purifying one type of DNA away from other DNA molecules -Plasmids from bacterial chromosomal DNA (Form) - phage DNA (Location) -Restriction fragments, PCR products (Size)
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8 SDS, alkali
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10 alkali neutralize
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11 RNA PURIFICATION Lyse & denature proteins FASTAcidic phenol Or bind glass/silica Small RNAs?
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15 A? B?C? M
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16 Oligo-dT beads for polyA+ mRNA
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17 High Salt
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20 Chemical Synthesis of oligonucleotides Uses? Block and unblock sequentially so that only one nucleotide adds at a time
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21 Phosphoramidite 5’ 3’ Protected amino groups * *
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22 Couple Growing chain Blocked 5’-OH
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23 Unblock 1st “nucleotide”
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24 Add and activate next “nucleotide”
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25 Couple
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26 Product 99%
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27 1% Cap
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29 1st nuc on bead. (blocked at 5’-OH) unblock couple cap Remove from bead Purify 3’- 5’ Add next nuc. (blocked 5’) De-protect Unblock 5’-OH
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30 PNA RNA harder DNA variants like
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33 If DNA is too large for conventional electrophoresis….
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34 Pulsed-field electrophoresis
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37 Polyacrylamide Gels can resolve small DNAs differing in length by one nucleotide
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38 Dideoxy sequencing converts sequence Information (A, C, G, T) into size differences e.g. if a DNA has T residues at positions 2, 5, 13, 16… this can be converted into a set of DNAs of length n+ 2, 5, 13, 16.. (which can be measured by denaturing polyacrylamide gel electrophoresis)
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40 ddCTP
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41 ddATP dCTP dGTP dTTP dATP LABEL
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42 2,5,13,16 9,10,15,19 1,4,7,8,12,14,20 3,6,11,17,18 ddA ddC ddG ddT
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44 2,5,13,16 9,10,15,19 1,4,7,8,12,14,20 3,6,11,17,18 ddA ddC ddG ddT n +
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46 2,5,13,16 9,10,15,19 1,4,7,8,12,14,20 3,6,11,17,18 ddA ddC ddG ddT
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47 ddA ddC ddG ddT
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50 What do you need to sequence DNA? Where do the reagents come from? Must the DNA be pure? How much is needed How much good sequence can you obtain?
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51 Nucleic acid hybridization Key to life and almost every procedure in molecular biology
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56 Hybridize to DNA on blot
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57 Recognized by specific Ab Recognized by (strept)avidin
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58 RNA Probe
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60 Northern RNA blot
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61 COLONY HYBRIDIZATION
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62 DNA (chromosome) in situ FISH
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66 RNA in situ with non-radioactive probe
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