Study guides › B/B › Biology
Biotechnology & Lab Techniques
The MCAT loves experiments built from these tools. You will learn how PCR, sequencing, restriction digests, gels, cloning, blotting, ELISA, and CRISPR work, and how to read their results and controls.
Study this chapter in PrepMed (free)
What this chapter covers
- PCR & DNA Sequencing. PCR and Sanger sequencing show up in experiment passages, usually with a question about controls or cycle math.
- Restriction Enzymes & Gel Electrophoresis. Predicting fragment sizes and reading band patterns is a classic MCAT calculation.
- Cloning, Plasmids & Recombinant DNA. Knowing why each part of a cloning workflow exists makes the experiment questions straightforward.
- Blots, Probes & ELISA. The trick is to match the blot to its target molecule and to interpret bands against a loading control.
- CRISPR, RNAi & Genome Tools. Gene editing questions test how a guide finds its target and how the cell repairs the cut.
Key points to know
- PCR: denature (95 °C), anneal (50-65 °C), extend (72 °C)
- Taq is heat stable; primers set the target boundaries
- Restriction sites are palindromic; EcoRI cuts G^AATTC and leaves sticky ends
- Circular DNA: n cuts give n fragments; linear DNA: n + 1
- Vector needs ori, a selectable marker, and an MCS
- Ligase seals sticky ends; transformation puts plasmids into cells
- SNoW DRoP: Southern DNA, Northern RNA, Western Protein
- Western blots use primary and labeled secondary antibodies
Try a practice question
Why is Taq polymerase used in PCR instead of E. coli DNA polymerase?
- It has a faster proofreading activity
- It copies RNA templates directly
- It survives the high temperature of the denaturation step
- It does not need primers
Show the answer
C. Taq comes from a heat-loving bacterium and remains active through repeated 95 °C denaturation steps. Like other DNA polymerases, it still needs primers and a DNA template.
Common questions
What does this chapter cover?
Biotechnology & Lab Techniques covers PCR & DNA Sequencing, Restriction Enzymes & Gel Electrophoresis, Cloning, Plasmids & Recombinant DNA, Blots, Probes & ELISA, CRISPR, RNAi & Genome Tools.
What should I know first?
PCR: denature (95 °C), anneal (50-65 °C), extend (72 °C) Taq is heat stable; primers set the target boundaries Restriction sites are palindromic; EcoRI cuts G^AATTC and leaves sticky ends
24 original practice questions accompany this chapter in the app. Spaced review brings missed ideas back at the right time; it helps memory but cannot promise you will not miss an idea again.