Comparing AFB and LED-Fluorescence Microscopy

Direct Microscopy for Acid Fast Bacilli (AFB)

Figure 1: Bright Field Microscope used in Ziehl–Neelsen (ZN) staining of AFB

Light Emission Diode (LED) 

Fluorescence Microscopy

Figure 2: LED-Fluorescent Microscope used in fluorescent staining of AFB

Figure 3: ZN-stained slide used in direct microscopy

Figure 4: Auramine-O-stained slide used in fluorescent microscopy

Method used widely for the diagnosis and confirmation of pulmonary tuberculosis

Method used less commonly for the diagnosis and confirmation of pulmonary tuberculosis

Staining procedure complex 

Staining procedure simpler

Examination at lower magnification is NOT possible

Examination at lower magnification is possible

Takes more time than LED-FM

Takes 75% less time than ZN and chances to lose scanty slides are also minimized.

Low durability

High durability

Less sensitive

10% more sensitivity than Bright Field ZN microscopy 

As specific as LED-FM

Equally as specific as ZN microscopy 

No need for an experienced lab technician

Needs an experienced lab technician

Technical errors are common

Technical errors are less common

Misses the paucibacillary TB cases, especially when the patient is co-infected with HIV

Identifies the paucibacillary TB cases especially when the patient is co-infected with HIV