Microbiology and Biotechnology Assignment Help & Online Tutoring

A microbiology tutor works through the lab assignment with you rather than submitting it for you. They explain the technique, show you how to calculate counts and growth rates from your own data and check your write-up, so the report stays your own and follows your institution's academic integrity rules.

Count the colonies on a plate, then divide by the volume plated in mL and multiply by the dilution factor. For example, 150 colonies from 0.1 mL of a 10⁻⁵ dilution gives 150 ÷ 0.1 × 10⁵, which is 1.5 × 10⁸ CFU per mL in the original sample.

Transfer a fixed volume into a fixed volume of diluent, mix well and repeat. A 1 mL into 9 mL transfer gives a tenfold dilution each step, so three steps give 10⁻³. Use a fresh tip for each transfer and label tubes with the cumulative dilution, not just each step.

Count plates with roughly 30 to 300 colonies, a range many lab manuals use. Fewer colonies give large random error, and more than about 300 makes colonies overlap and hard to count. Report the dilution and volume plated, and average replicate plates at the same dilution.

A batch culture shows four phases. In the lag phase cells adapt and prepare to divide. In the exponential or log phase they divide at a constant rate. In the stationary phase growth equals death as nutrients run out, and in the death phase viable numbers fall.

Use two points from the exponential phase. The number of generations equals log N minus log N₀, divided by log 2, and generation time is the elapsed time divided by the number of generations. Take both points from the straight part of a semi-log plot.

Plot time on the x-axis and the logarithm of cell number or optical density on the y-axis, or use a semi-log scale. The exponential phase then appears as a straight line, which makes it easy to identify phases and calculate the specific growth rate and generation time.

Gram-positive bacteria have a thick peptidoglycan wall that keeps the crystal violet–iodine complex, so they stain purple. Gram-negative bacteria have a thin wall and an outer membrane, lose the stain during decolourisation, and take up the safranin counterstain, so they appear pink or red.

Aseptic technique is the set of practices that stop contamination of cultures and protect you. It includes working near a flame or in a safety cabinet, flaming loops, minimising the time containers are open, disinfecting the bench and labelling everything clearly. Markers often check it in practical assessments.

Measure the diameter of each inhibition zone in millimetres, including the disc. Compare it with the breakpoints for that organism and antibiotic in the standard your lab uses, such as CLSI or EUCAST, to classify the result as susceptible, intermediate or resistant. Do not compare zones between different antibiotics directly.

In batch culture, nutrients are added once and the culture passes through lag, exponential, stationary and death phases. In continuous culture, fresh medium is added and culture removed at the same rate, keeping cells in a steady exponential state. Chemostats are a common continuous system.

Horizontal gene transfer is the movement of genes between organisms other than from parent to offspring. In bacteria it happens by transformation, uptake of free DNA, transduction, transfer by viruses, and conjugation, transfer through direct contact. It spreads antibiotic resistance genes between species.

Bacteria gain resistance through mutations or by acquiring resistance genes by horizontal gene transfer. Common mechanisms include enzymes that destroy the drug, such as beta-lactamases, changes to the drug's target, pumps that remove the drug and reduced entry into the cell. Overuse of antibiotics selects for resistant strains.

Yes. Tutors support BSc, BTech and MSc students with lab calculations, technique questions, practical write-ups, data analysis and project reports. They follow your own lab manual and marking criteria and explain how to present gels, plates and growth data clearly and accurately.

You get step-by-step working for your calculations, an explanation of each technique and control, help interpreting your own data and a tutor check of your lab report. Help can be live one-to-one lessons, written worked solutions or guidance on a graded report, depending on your needs.

Short calculations can often be answered the same day, depending on tutor availability. Full lab reports depend on their length, the amount of data and your deadline, which you give when you ask for a quote. Sending your data early leaves time for questions and checking.

The price depends on the type of task, your level and your deadline. You see a free quote before you pay, with a fixed price for written guidance or an hourly rate for live lessons. There is no contract or minimum number of sessions, and refunds follow our published policy.

Yes, when it supports your learning. Tutoring, explanations, feedback on drafts and practice with similar calculations are generally allowed. Submitting work written by someone else is not. Check your institution's academic integrity policy, and use your own lab data and words in your report.

Yes. Your data, files and personal details are kept private and shared only with the tutor working on your request. We do not publish your work or contact your institution, and you can ask for your files to be deleted once your request is complete.