Good laboratory practices
- Before You Begin Good laboratory practices for PCR and RT-PCR
Precautions: To avoid contamination, perform the workflow setup under DNA-free conditions. This includes:
- Prepare and pipette all solutions with nuclease-free, DNA-free equipment and consumables.
- UV-treat or the laminar flow hood prior to pipetting.
- Use sterile single-use gloves and freshly laundered laboratory coats. Change gloves if you suspect that they are contaminated.
- Close vials immediately after pipetting. Avoid splashing or spraying samples.
- Spatial segregation of the sequential workflow steps.
Rooms |
Workflow Step |
Sample preparation room |
Extraction and purification of test samples, including preparation of recovery control sample. |
Master mix preparation room |
Master mix preparation and pipetting of PCR Negative Control to the NTC wells. |
PCR room for setup and amplification run |
Dilution and pipetting of samples and PCR Positive Control to the PCR plate. |
Note: Do not use disinfectants during Sample preparation experiments so as not to affect the results. |
- Avoiding false positives due to cross-contamination
To avoid false positives due to cross-contamination:
- Use a positive-displacement pipettor or aerosol‑resistant barrier pipette tips.
- Prepare and close all negative control and unknown sample tubes before pipetting the positive control.
- Do not open tubes after amplification.
- Use different sets of pipettors when pipetting negative control, unknown, and positive control samples.
- In the process of preparing the sample, dispense tubes in sequence from left to right the: negative controls, un-known samples and ERCs, and positive controls .